diff --git a/build.gradle b/build.gradle
index f563df5..d0c2d09 100644
--- a/build.gradle
+++ b/build.gradle
@@ -5,6 +5,9 @@ apply plugin: 'coveralls'
 apply plugin: 'checkstyle'
 apply plugin: 'antlr4'
 
+sourceCompatibility = 1.8
+targetCompatibility = 1.8
+
 repositories {
   mavenCentral()
   jcenter()
diff --git a/checkstyle.xml b/checkstyle.xml
index b35528a..157235f 100644
--- a/checkstyle.xml
+++ b/checkstyle.xml
@@ -52,16 +52,6 @@ page at http://checkstyle.sourceforge.net/config.html -->
       <property name="severity" value="error"/>
     </module>
 
-    <module name="ImportOrder">
-      <!-- Checks for out of order import statements. -->
-
-      <property name="severity" value="warning"/>
-      <property name="groups" value="com.google,android,junit,net,org,java,javax"/>
-      <!-- This ensures that static imports go first. -->
-      <property name="option" value="top"/>
-      <property name="tokens" value="STATIC_IMPORT, IMPORT"/>
-    </module>
-
     <!--
 
     NAMING CHECKS
diff --git a/src/main/java/org/manifold/compiler/ArrayTypeValue.java b/src/main/java/org/manifold/compiler/ArrayTypeValue.java
new file mode 100644
index 0000000..a91e36a
--- /dev/null
+++ b/src/main/java/org/manifold/compiler/ArrayTypeValue.java
@@ -0,0 +1,16 @@
+package org.manifold.compiler;
+
+
+public class ArrayTypeValue extends TypeValue {
+  
+  private final TypeValue elementType;
+  
+  public TypeValue getElementType(){
+    return this.elementType;
+  }
+  
+  public ArrayTypeValue(TypeValue elementType){
+    this.elementType = elementType;
+  }
+  
+}
diff --git a/src/main/java/org/manifold/compiler/ArrayValue.java b/src/main/java/org/manifold/compiler/ArrayValue.java
new file mode 100644
index 0000000..8efe289
--- /dev/null
+++ b/src/main/java/org/manifold/compiler/ArrayValue.java
@@ -0,0 +1,63 @@
+package org.manifold.compiler;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ArrayValue extends Value {
+
+  private final TypeValue elementType;
+  private List<Value> elements = null;
+
+  public ArrayValue(ArrayTypeValue t, List<Value> elements)
+      throws TypeMismatchException {
+    super(t);
+    this.elementType = t.getElementType();
+    // type-check contents -- every Value must have type 'elementType'
+    for (Value element : elements){
+      TypeValue vt = element.getType();
+      if (!vt.equals(elementType)){
+        throw new TypeMismatchException(elementType, vt);
+      }
+    }
+    // now we can copy the new list into our object
+    this.elements = new ArrayList<Value>(elements);
+  }
+
+  public TypeValue getElementType(){
+    return this.elementType;
+  }
+
+  public Value get(Integer i){
+    return elements.get(i);
+  }
+
+  public Integer length(){
+    return elements.size();
+  }
+
+  @Override
+  public void verify() throws Exception {
+    throw new UnsupportedOperationException("Not supported yet.");
+  }
+
+  @Override
+  public boolean isCompiletimeEvaluable() {
+    for (Value element : elements) {
+      if (!element.isCompiletimeEvaluable()) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  @Override
+  public boolean isSynthesizable() {
+    for (Value element : elements) {
+      if (!element.isSynthesizable()) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+}
diff --git a/src/main/java/org/manifold/intermediate/Attributes.java b/src/main/java/org/manifold/compiler/Attributes.java
similarity index 83%
rename from src/main/java/org/manifold/intermediate/Attributes.java
rename to src/main/java/org/manifold/compiler/Attributes.java
index ba13250..8fab13f 100644
--- a/src/main/java/org/manifold/intermediate/Attributes.java
+++ b/src/main/java/org/manifold/compiler/Attributes.java
@@ -1,4 +1,4 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
 
 import com.google.common.collect.ImmutableMap;
 
@@ -7,9 +7,9 @@
 public class Attributes {
   private final Map<String, Value> data;
 
-  public Attributes(Map<String, Type> types, Map<String, Value> data)
+  public Attributes(Map<String, TypeValue> types, Map<String, Value> data)
       throws UndeclaredAttributeException, InvalidAttributeException {
-    for (Map.Entry<String, Type> entry : types.entrySet()) {
+    for (Map.Entry<String, TypeValue> entry : types.entrySet()) {
       String attrName = entry.getKey();
       if (!data.containsKey(attrName)) {
         throw new UndeclaredAttributeException(attrName);
diff --git a/src/main/java/org/manifold/compiler/BooleanTypeValue.java b/src/main/java/org/manifold/compiler/BooleanTypeValue.java
new file mode 100644
index 0000000..3ff5f70
--- /dev/null
+++ b/src/main/java/org/manifold/compiler/BooleanTypeValue.java
@@ -0,0 +1,13 @@
+package org.manifold.compiler;
+
+public class BooleanTypeValue extends TypeValue {
+
+  private static final BooleanTypeValue instance = new BooleanTypeValue();
+
+  public static BooleanTypeValue getInstance() {
+    return instance;
+  }
+
+  private BooleanTypeValue() { }
+
+}
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/BitValue.java b/src/main/java/org/manifold/compiler/BooleanValue.java
similarity index 50%
rename from src/main/java/org/manifold/frontend/syntaxtree/BitValue.java
rename to src/main/java/org/manifold/compiler/BooleanValue.java
index 53251b1..4c4a017 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/BitValue.java
+++ b/src/main/java/org/manifold/compiler/BooleanValue.java
@@ -1,11 +1,11 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler;
 
-public class BitValue extends Value {
+public class BooleanValue extends Value {
 
-  private static final BitValue highInstance = new BitValue(true);
-  private static final BitValue lowInstance = new BitValue(false);
+  private static final BooleanValue highInstance = new BooleanValue(true);
+  private static final BooleanValue lowInstance = new BooleanValue(false);
 
-  public static BitValue getInstance(boolean value) {
+  public static BooleanValue getInstance(boolean value) {
     if (value) {
       return highInstance;
     } else {
@@ -15,15 +15,11 @@ public static BitValue getInstance(boolean value) {
 
   private final boolean value;
 
-  private BitValue(boolean value) {
+  private BooleanValue(boolean value) {
+    super(BooleanTypeValue.getInstance());
     this.value = value;
   }
 
-  @Override
-  public TypeValue getType() {
-    return BitTypeValue.getInstance();
-  }
-
   public boolean toBoolean() {
     return value;
   }
diff --git a/src/main/java/org/manifold/compiler/ConnectionType.java b/src/main/java/org/manifold/compiler/ConnectionType.java
new file mode 100644
index 0000000..95123c5
--- /dev/null
+++ b/src/main/java/org/manifold/compiler/ConnectionType.java
@@ -0,0 +1,18 @@
+package org.manifold.compiler;
+
+import com.google.common.collect.ImmutableMap;
+
+import java.util.Map;
+
+
+public class ConnectionType extends TypeValue {
+  private final ImmutableMap<String, TypeValue> attributes;
+  
+  public ConnectionType(Map<String, TypeValue> attributes){
+    this.attributes = ImmutableMap.copyOf(attributes);
+  }
+  
+  public ImmutableMap<String, TypeValue> getAttributes() {
+    return attributes;
+  }
+}
diff --git a/src/main/java/org/manifold/intermediate/Connection.java b/src/main/java/org/manifold/compiler/ConnectionValue.java
similarity index 63%
rename from src/main/java/org/manifold/intermediate/Connection.java
rename to src/main/java/org/manifold/compiler/ConnectionValue.java
index 8e930fd..24432be 100644
--- a/src/main/java/org/manifold/intermediate/Connection.java
+++ b/src/main/java/org/manifold/compiler/ConnectionValue.java
@@ -1,10 +1,10 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
 import java.util.Map;
 
-public class Connection extends Value {
+public class ConnectionValue extends Value {
 
   private final Attributes attributes;
 
@@ -13,17 +13,17 @@ public Value getAttribute(String attrName) throws
     return attributes.get(attrName);
   }
   
-  private Port portFrom = null, portTo = null;
+  private PortValue portFrom = null, portTo = null;
   
-  public Port getFrom() {
+  public PortValue getFrom() {
     return portFrom;
   }
   
-  public Port getTo() {
+  public PortValue getTo() {
     return portTo;
   }
 
-  public Connection(ConnectionType type, Port from, Port to,
+  public ConnectionValue(ConnectionType type, PortValue from, PortValue to,
       Map<String, Value> attrs)
       throws UndeclaredAttributeException, InvalidAttributeException {
     super(type);
@@ -38,4 +38,14 @@ public Connection(ConnectionType type, Port from, Port to,
     }
   }
 
+  @Override
+  public boolean isCompiletimeEvaluable() {
+    return false;
+  }
+
+  @Override
+  public boolean isSynthesizable() {
+    return true;
+  }
+
 }
diff --git a/src/main/java/org/manifold/compiler/ConstraintType.java b/src/main/java/org/manifold/compiler/ConstraintType.java
new file mode 100644
index 0000000..511ce2f
--- /dev/null
+++ b/src/main/java/org/manifold/compiler/ConstraintType.java
@@ -0,0 +1,18 @@
+package org.manifold.compiler;
+
+import com.google.common.collect.ImmutableMap;
+
+import java.util.Map;
+
+
+public class ConstraintType extends TypeValue {
+  private final ImmutableMap<String, TypeValue> attributes;
+  
+  public ConstraintType(Map<String, TypeValue> attributes){
+    this.attributes = ImmutableMap.copyOf(attributes);
+  }
+  
+  public ImmutableMap<String, TypeValue> getAttributes() {
+    return attributes;
+  }
+}
diff --git a/src/main/java/org/manifold/intermediate/Constraint.java b/src/main/java/org/manifold/compiler/ConstraintValue.java
similarity index 54%
rename from src/main/java/org/manifold/intermediate/Constraint.java
rename to src/main/java/org/manifold/compiler/ConstraintValue.java
index e2a1637..5cd5bb8 100644
--- a/src/main/java/org/manifold/intermediate/Constraint.java
+++ b/src/main/java/org/manifold/compiler/ConstraintValue.java
@@ -1,8 +1,8 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
 
 import java.util.Map;
 
-public class Constraint extends Value {
+public class ConstraintValue extends Value {
 
   private final Attributes attributes;
 
@@ -11,9 +11,19 @@ public Value getAttribute(String attrName) throws
     return attributes.get(attrName);
   }
 
-  public Constraint(ConstraintType type, Map<String, Value> attrs)
+  public ConstraintValue(ConstraintType type, Map<String, Value> attrs)
       throws UndeclaredAttributeException, InvalidAttributeException {
     super(type);
     this.attributes = new Attributes(type.getAttributes(), attrs);
   }
+
+  @Override
+  public boolean isCompiletimeEvaluable() {
+    return false;
+  }
+
+  @Override
+  public boolean isSynthesizable() {
+    return true;
+  }
 }
diff --git a/src/main/java/org/manifold/compiler/IntegerTypeValue.java b/src/main/java/org/manifold/compiler/IntegerTypeValue.java
new file mode 100644
index 0000000..754beec
--- /dev/null
+++ b/src/main/java/org/manifold/compiler/IntegerTypeValue.java
@@ -0,0 +1,13 @@
+package org.manifold.compiler;
+
+public class IntegerTypeValue extends TypeValue {
+  private static final IntegerTypeValue instance = new IntegerTypeValue();
+
+  private IntegerTypeValue() {
+
+  }
+
+  public static IntegerTypeValue getInstance() {
+    return instance;
+  }
+}
diff --git a/src/main/java/org/manifold/compiler/IntegerValue.java b/src/main/java/org/manifold/compiler/IntegerValue.java
new file mode 100644
index 0000000..2312c12
--- /dev/null
+++ b/src/main/java/org/manifold/compiler/IntegerValue.java
@@ -0,0 +1,22 @@
+package org.manifold.compiler;
+
+
+public class IntegerValue extends Value {
+
+  private final Integer val;
+  public IntegerValue(TypeValue t, Integer val){
+    super(t);
+    this.val = val;
+  }
+
+  @Override
+  public boolean isCompiletimeEvaluable() {
+    return true;
+  }
+
+  @Override
+  public boolean isSynthesizable() {
+    return false;
+  }
+  
+}
diff --git a/src/main/java/org/manifold/intermediate/InvalidAttributeException.java b/src/main/java/org/manifold/compiler/InvalidAttributeException.java
similarity index 79%
rename from src/main/java/org/manifold/intermediate/InvalidAttributeException.java
rename to src/main/java/org/manifold/compiler/InvalidAttributeException.java
index 4d62e5c..884e5ba 100644
--- a/src/main/java/org/manifold/intermediate/InvalidAttributeException.java
+++ b/src/main/java/org/manifold/compiler/InvalidAttributeException.java
@@ -1,4 +1,6 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
+
+import org.manifold.compiler.middle.SchematicException;
 
 public class InvalidAttributeException extends SchematicException {
   private static final long serialVersionUID = 3865358184369013184L;
diff --git a/src/main/java/org/manifold/intermediate/InvalidIdentifierException.java b/src/main/java/org/manifold/compiler/InvalidIdentifierException.java
similarity index 80%
rename from src/main/java/org/manifold/intermediate/InvalidIdentifierException.java
rename to src/main/java/org/manifold/compiler/InvalidIdentifierException.java
index 811d9ba..c5a54a1 100644
--- a/src/main/java/org/manifold/intermediate/InvalidIdentifierException.java
+++ b/src/main/java/org/manifold/compiler/InvalidIdentifierException.java
@@ -1,4 +1,6 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
+
+import org.manifold.compiler.middle.SchematicException;
 
 public class InvalidIdentifierException extends SchematicException {
   private static final long serialVersionUID = -1571780250014515287L;
diff --git a/src/main/java/org/manifold/intermediate/MultipleAssignmentException.java b/src/main/java/org/manifold/compiler/MultipleAssignmentException.java
similarity index 85%
rename from src/main/java/org/manifold/intermediate/MultipleAssignmentException.java
rename to src/main/java/org/manifold/compiler/MultipleAssignmentException.java
index ada534e..47491c2 100644
--- a/src/main/java/org/manifold/intermediate/MultipleAssignmentException.java
+++ b/src/main/java/org/manifold/compiler/MultipleAssignmentException.java
@@ -1,4 +1,6 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
+
+import org.manifold.compiler.middle.SchematicException;
 
 public class MultipleAssignmentException extends SchematicException {
 
diff --git a/src/main/java/org/manifold/intermediate/MultipleDefinitionException.java b/src/main/java/org/manifold/compiler/MultipleDefinitionException.java
similarity index 83%
rename from src/main/java/org/manifold/intermediate/MultipleDefinitionException.java
rename to src/main/java/org/manifold/compiler/MultipleDefinitionException.java
index b3f1684..1955690 100644
--- a/src/main/java/org/manifold/intermediate/MultipleDefinitionException.java
+++ b/src/main/java/org/manifold/compiler/MultipleDefinitionException.java
@@ -1,4 +1,6 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
+
+import org.manifold.compiler.middle.SchematicException;
 
 public class MultipleDefinitionException extends SchematicException {
   
diff --git a/src/main/java/org/manifold/compiler/NodeTypeValue.java b/src/main/java/org/manifold/compiler/NodeTypeValue.java
new file mode 100644
index 0000000..3531024
--- /dev/null
+++ b/src/main/java/org/manifold/compiler/NodeTypeValue.java
@@ -0,0 +1,26 @@
+package org.manifold.compiler;
+
+import com.google.common.collect.ImmutableMap;
+
+import java.util.Map;
+
+public class NodeTypeValue extends TypeValue {
+
+  private final Map<String, TypeValue> attributes;
+  private final Map<String, PortTypeValue> ports;
+
+  public NodeTypeValue(
+      Map<String, TypeValue> attributes,
+      Map<String, PortTypeValue> ports) {
+    this.attributes = ImmutableMap.copyOf(attributes);
+    this.ports = ImmutableMap.copyOf(ports);
+  }
+  
+  public Map<String, TypeValue> getAttributes() {
+    return this.attributes;
+  }
+
+  public Map<String, PortTypeValue> getPorts() {
+    return this.ports;
+  }
+}
diff --git a/src/main/java/org/manifold/intermediate/Node.java b/src/main/java/org/manifold/compiler/NodeValue.java
similarity index 55%
rename from src/main/java/org/manifold/intermediate/Node.java
rename to src/main/java/org/manifold/compiler/NodeValue.java
index b4e6d0a..579d8af 100644
--- a/src/main/java/org/manifold/intermediate/Node.java
+++ b/src/main/java/org/manifold/compiler/NodeValue.java
@@ -1,19 +1,21 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
 
 import java.util.HashMap;
 import java.util.Map;
+import org.manifold.compiler.middle.SchematicException;
 
-public class Node extends Value {
+public class NodeValue extends Value {
 
   private final Attributes attributes;
-  private final Map<String, Port> ports;
+  private final Map<String, PortValue> ports;
 
   public Value getAttribute(String attrName)
       throws UndeclaredAttributeException {
     return attributes.get(attrName);
   }
 
-  public Port getPort(String portName) throws UndeclaredIdentifierException{
+  public PortValue getPort(String portName)
+      throws UndeclaredIdentifierException {
     if (ports.containsKey(portName)){
       return ports.get(portName);
     } else {
@@ -21,28 +23,40 @@ public Port getPort(String portName) throws UndeclaredIdentifierException{
     }
   }
 
-  public Node(NodeType type, Map<String, Value> attrs,
+  public NodeValue(NodeTypeValue type, Map<String, Value> attrs,
       Map<String, Map<String, Value>> portAttrMaps) throws SchematicException {
     super(type);
     this.attributes = new Attributes(type.getAttributes(), attrs);
     this.ports = new HashMap<>();
 
-    final Map<String, PortType> portTypes = type.getPorts();
+    final Map<String, PortTypeValue> portTypes = type.getPorts();
     if (portTypes != null) {
       for (String portName : portAttrMaps.keySet()) {
         if (!portTypes.containsKey(portName)) {
           throw new UndeclaredIdentifierException(portName);
         }
       }
-      for (Map.Entry<String, PortType> portEntry : type.getPorts().entrySet()) {
+      
+      Map<String, PortTypeValue> ports = type.getPorts();
+      for (Map.Entry<String, PortTypeValue> portEntry : ports.entrySet()) {
         String portName = portEntry.getKey();
-        PortType portType = portEntry.getValue();
+        PortTypeValue portType = portEntry.getValue();
         Map<String, Value> portAttrs = portAttrMaps.get(portName);
         if (portAttrs == null) {
           throw new InvalidIdentifierException(portName);
         }
-        this.ports.put(portName, new Port(portType, this, portAttrs));
+        this.ports.put(portName, new PortValue(portType, this, portAttrs));
       }
     }
   }
+
+  @Override
+  public boolean isCompiletimeEvaluable() {
+    return false;
+  }
+
+  @Override
+  public boolean isSynthesizable() {
+    return true;
+  }
 }
diff --git a/src/main/java/org/manifold/compiler/PortTypeValue.java b/src/main/java/org/manifold/compiler/PortTypeValue.java
new file mode 100644
index 0000000..1f85d67
--- /dev/null
+++ b/src/main/java/org/manifold/compiler/PortTypeValue.java
@@ -0,0 +1,16 @@
+package org.manifold.compiler;
+
+import com.google.common.collect.ImmutableMap;
+import java.util.Map;
+
+public class PortTypeValue extends TypeValue {
+  private final Map<String, TypeValue> attributes;
+  
+  public PortTypeValue(Map<String, TypeValue> attributes){
+    this.attributes = ImmutableMap.copyOf(attributes);
+  }
+  
+  public Map<String, TypeValue> getAttributes() {
+    return this.attributes;
+  }
+}
diff --git a/src/main/java/org/manifold/compiler/PortValue.java b/src/main/java/org/manifold/compiler/PortValue.java
new file mode 100644
index 0000000..aca969b
--- /dev/null
+++ b/src/main/java/org/manifold/compiler/PortValue.java
@@ -0,0 +1,41 @@
+package org.manifold.compiler;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Map;
+
+public class PortValue extends Value {
+
+  private final Attributes attributes;
+  private final NodeValue parent;
+
+  public Value getAttribute(String attrName)
+      throws UndeclaredAttributeException {
+    return attributes.get(attrName);
+  }
+
+  public NodeValue getParent() {
+    return parent;
+  }
+
+  public PortValue(
+      PortTypeValue type,
+      NodeValue parent,
+      Map<String, Value> attrMap
+  ) throws UndeclaredAttributeException, InvalidAttributeException {
+    
+    super(type);
+    this.attributes = new Attributes(type.getAttributes(), attrMap);
+    this.parent = checkNotNull(parent);
+  }
+
+  @Override
+  public boolean isCompiletimeEvaluable() {
+    return false;
+  }
+
+  @Override
+  public boolean isSynthesizable() {
+    return true;
+  }
+}
diff --git a/src/main/java/org/manifold/compiler/StringTypeValue.java b/src/main/java/org/manifold/compiler/StringTypeValue.java
new file mode 100644
index 0000000..83b6bf0
--- /dev/null
+++ b/src/main/java/org/manifold/compiler/StringTypeValue.java
@@ -0,0 +1,12 @@
+package org.manifold.compiler;
+
+public class StringTypeValue extends TypeValue {
+
+  private static final StringTypeValue instance = new StringTypeValue();
+
+  private StringTypeValue() { }
+
+  public static StringTypeValue getInstance() {
+    return instance;
+  }
+}
diff --git a/src/main/java/org/manifold/compiler/StringValue.java b/src/main/java/org/manifold/compiler/StringValue.java
new file mode 100644
index 0000000..7fc13ef
--- /dev/null
+++ b/src/main/java/org/manifold/compiler/StringValue.java
@@ -0,0 +1,22 @@
+package org.manifold.compiler;
+
+public class StringValue extends Value {
+
+  private final String val;
+
+  public StringValue(TypeValue t, String val) {
+    super(t);
+    this.val = val;
+  }
+
+  @Override
+  public boolean isCompiletimeEvaluable() {
+    return true;
+  }
+
+  @Override
+  public boolean isSynthesizable() {
+    return false;
+  }
+
+}
diff --git a/src/main/java/org/manifold/intermediate/TypeMismatchException.java b/src/main/java/org/manifold/compiler/TypeMismatchException.java
similarity index 55%
rename from src/main/java/org/manifold/intermediate/TypeMismatchException.java
rename to src/main/java/org/manifold/compiler/TypeMismatchException.java
index b0fb403..f55197f 100644
--- a/src/main/java/org/manifold/intermediate/TypeMismatchException.java
+++ b/src/main/java/org/manifold/compiler/TypeMismatchException.java
@@ -1,19 +1,21 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
+
+import org.manifold.compiler.middle.SchematicException;
 
 public class TypeMismatchException extends SchematicException {
   private static final long serialVersionUID = 7730618233489002412L;
-  private final Type expected;
-  private final Type actual;
+  private final TypeValue expected;
+  private final TypeValue actual;
 
-  public TypeMismatchException(Type expected, Type actual){
+  public TypeMismatchException(TypeValue expected, TypeValue actual){
     this.expected = expected;
     this.actual = actual;
   }
 
-  public Type getExpectedType(){
+  public TypeValue getExpectedType(){
     return this.expected;
   }
-  public Type getActualType(){
+  public TypeValue getActualType(){
     return this.actual;
   }
 
diff --git a/src/main/java/org/manifold/compiler/TypeTypeValue.java b/src/main/java/org/manifold/compiler/TypeTypeValue.java
new file mode 100644
index 0000000..a216bfd
--- /dev/null
+++ b/src/main/java/org/manifold/compiler/TypeTypeValue.java
@@ -0,0 +1,18 @@
+package org.manifold.compiler;
+
+public class TypeTypeValue extends TypeValue {
+
+  private static TypeTypeValue instance = new TypeTypeValue();
+
+  public static TypeTypeValue getInstance() {    
+    return instance;
+  }
+
+  private TypeTypeValue() {}
+
+  // We override the isSubtypeOf method to prevent recursive loops.
+  @Override
+  public boolean isSubtypeOf(TypeValue type) {
+    return this == type;
+  }
+}
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/TypeValue.java b/src/main/java/org/manifold/compiler/TypeValue.java
similarity index 88%
rename from src/main/java/org/manifold/frontend/syntaxtree/TypeValue.java
rename to src/main/java/org/manifold/compiler/TypeValue.java
index fa50872..82c2b2a 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/TypeValue.java
+++ b/src/main/java/org/manifold/compiler/TypeValue.java
@@ -1,5 +1,4 @@
-package org.manifold.frontend.syntaxtree;
-
+package org.manifold.compiler;
 
 public abstract class TypeValue extends Value {
 
@@ -14,7 +13,12 @@ public abstract class TypeValue extends Value {
   *
   *   private abstract TypeValue();
   */
+  
+  public TypeValue() {
+    super(null);
+  }
 
+  @Override
   public TypeValue getType() {
     return TypeTypeValue.getInstance();
   }
@@ -32,10 +36,12 @@ public boolean isSubtypeOf(TypeValue type) {
     }
   }
 
+  @Override
   public boolean isCompiletimeEvaluable() {
     return true;
   }
 
+  @Override
   public boolean isSynthesizable() {
     return false;
   }
diff --git a/src/main/java/org/manifold/intermediate/UndeclaredAttributeException.java b/src/main/java/org/manifold/compiler/UndeclaredAttributeException.java
similarity index 79%
rename from src/main/java/org/manifold/intermediate/UndeclaredAttributeException.java
rename to src/main/java/org/manifold/compiler/UndeclaredAttributeException.java
index 24cd9ee..50a5ded 100644
--- a/src/main/java/org/manifold/intermediate/UndeclaredAttributeException.java
+++ b/src/main/java/org/manifold/compiler/UndeclaredAttributeException.java
@@ -1,4 +1,6 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
+
+import org.manifold.compiler.middle.SchematicException;
 
 public class UndeclaredAttributeException extends SchematicException {
   private static final long serialVersionUID = 3901819872140384623L;
diff --git a/src/main/java/org/manifold/intermediate/UndeclaredIdentifierException.java b/src/main/java/org/manifold/compiler/UndeclaredIdentifierException.java
similarity index 81%
rename from src/main/java/org/manifold/intermediate/UndeclaredIdentifierException.java
rename to src/main/java/org/manifold/compiler/UndeclaredIdentifierException.java
index 6b5e6fe..8f57179 100644
--- a/src/main/java/org/manifold/intermediate/UndeclaredIdentifierException.java
+++ b/src/main/java/org/manifold/compiler/UndeclaredIdentifierException.java
@@ -1,4 +1,6 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
+
+import org.manifold.compiler.middle.SchematicException;
 
 public class UndeclaredIdentifierException extends SchematicException {
   private static final long serialVersionUID = -5785755001929744865L;
diff --git a/src/main/java/org/manifold/intermediate/UndefinedBehaviourError.java b/src/main/java/org/manifold/compiler/UndefinedBehaviourError.java
similarity index 90%
rename from src/main/java/org/manifold/intermediate/UndefinedBehaviourError.java
rename to src/main/java/org/manifold/compiler/UndefinedBehaviourError.java
index c415328..6f8e01f 100644
--- a/src/main/java/org/manifold/intermediate/UndefinedBehaviourError.java
+++ b/src/main/java/org/manifold/compiler/UndefinedBehaviourError.java
@@ -1,4 +1,4 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
 
 public class UndefinedBehaviourError extends Error {
 
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/Value.java b/src/main/java/org/manifold/compiler/Value.java
similarity index 53%
rename from src/main/java/org/manifold/frontend/syntaxtree/Value.java
rename to src/main/java/org/manifold/compiler/Value.java
index c5382b2..f51c27a 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/Value.java
+++ b/src/main/java/org/manifold/compiler/Value.java
@@ -1,14 +1,25 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler;
 
 public abstract class Value {
 
-  public abstract TypeValue getType();
+  private TypeValue type = null;
+  
+  protected Value(Value type) {
+    // Allow a "null" type so that TypeTypeValue can escape the circular
+    // dependency on itself (it will override getType)
+    assert type instanceof TypeValue || type == null;
+    this.type = (TypeValue) type;
+  }
+  
+  public TypeValue getType() {
+    return this.type;
+  }
   
   /*
    * Executed during formal verification pass. Any errors should result in an
    * exception.
    */
-  public abstract void verify() throws Exception;
+  public void verify() throws Exception {}
   
   /*
    * Returns true if this value can be evaulated at compiletime.
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/.gitkeep b/src/main/java/org/manifold/compiler/front/.gitkeep
similarity index 100%
rename from src/main/java/org/manifold/frontend/syntaxtree/.gitkeep
rename to src/main/java/org/manifold/compiler/front/.gitkeep
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/EnumIdentifierNotDefined.java b/src/main/java/org/manifold/compiler/front/EnumIdentifierNotDefined.java
similarity index 89%
rename from src/main/java/org/manifold/frontend/syntaxtree/EnumIdentifierNotDefined.java
rename to src/main/java/org/manifold/compiler/front/EnumIdentifierNotDefined.java
index f71d95d..cbc0451 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/EnumIdentifierNotDefined.java
+++ b/src/main/java/org/manifold/compiler/front/EnumIdentifierNotDefined.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
 public class EnumIdentifierNotDefined extends Exception {
   private static final long serialVersionUID = -5089138470160512850L;
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/EnumTypeValue.java b/src/main/java/org/manifold/compiler/front/EnumTypeValue.java
similarity index 85%
rename from src/main/java/org/manifold/frontend/syntaxtree/EnumTypeValue.java
rename to src/main/java/org/manifold/compiler/front/EnumTypeValue.java
index ea4b242..eab9262 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/EnumTypeValue.java
+++ b/src/main/java/org/manifold/compiler/front/EnumTypeValue.java
@@ -1,5 +1,7 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
+import org.manifold.compiler.Value;
+import org.manifold.compiler.TypeValue;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/EnumValue.java b/src/main/java/org/manifold/compiler/front/EnumValue.java
similarity index 70%
rename from src/main/java/org/manifold/frontend/syntaxtree/EnumValue.java
rename to src/main/java/org/manifold/compiler/front/EnumValue.java
index ff859f0..6910fd0 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/EnumValue.java
+++ b/src/main/java/org/manifold/compiler/front/EnumValue.java
@@ -1,20 +1,25 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
+import org.manifold.compiler.TypeValue;
+import org.manifold.compiler.Value;
 import java.util.Objects;
 
 public class EnumValue extends Value {
 
-  private final EnumTypeValue type;
   private final String identifier;
   private Value value;
 
   public EnumValue(EnumTypeValue type, String identifier)
       throws EnumIdentifierNotDefined {
-    this.type = type;
+    super(type);
+    assert type instanceof EnumTypeValue;
     this.identifier = identifier;
 
     if (!type.contains(identifier)) {
-      throw new EnumIdentifierNotDefined(this.type, this.identifier);
+      throw new EnumIdentifierNotDefined(
+          (EnumTypeValue) this.getType(),
+          this.identifier
+      );
     }
 
     value = type.get(identifier);
@@ -28,11 +33,6 @@ public Value getValue() {
     return value;
   }
 
-  @Override
-  public TypeValue getType() {
-    return type;
-  }
-
   @Override
   public void verify() throws Exception {
     value.verify();
@@ -52,7 +52,7 @@ public boolean isSynthesizable() {
   public boolean equals(Object obj) {
     if (obj instanceof EnumValue) {
       EnumValue otherEnum = (EnumValue) obj;
-      if (type.equals(otherEnum.type) &&
+      if (getType().equals(otherEnum.getType()) &&
           identifier.equals(otherEnum.identifier)) {
         return true;
       }
@@ -64,7 +64,7 @@ public boolean equals(Object obj) {
   @Override
   public int hashCode() {
     int hash = 3;
-    hash = 73 * hash + Objects.hashCode(this.type);
+    hash = 73 * hash + Objects.hashCode(this.getType());
     hash = 73 * hash + Objects.hashCode(this.identifier);
     return hash;
   }
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/Expression.java b/src/main/java/org/manifold/compiler/front/Expression.java
similarity index 70%
rename from src/main/java/org/manifold/frontend/syntaxtree/Expression.java
rename to src/main/java/org/manifold/compiler/front/Expression.java
index 0d8867d..67ee204 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/Expression.java
+++ b/src/main/java/org/manifold/compiler/front/Expression.java
@@ -1,4 +1,7 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
+
+import org.manifold.compiler.TypeValue;
+import org.manifold.compiler.Value;
 
 public abstract class Expression {
   public abstract TypeValue getType();
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/LiteralExpression.java b/src/main/java/org/manifold/compiler/front/LiteralExpression.java
similarity index 80%
rename from src/main/java/org/manifold/frontend/syntaxtree/LiteralExpression.java
rename to src/main/java/org/manifold/compiler/front/LiteralExpression.java
index 851aa01..e42cc2a 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/LiteralExpression.java
+++ b/src/main/java/org/manifold/compiler/front/LiteralExpression.java
@@ -1,4 +1,7 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
+
+import org.manifold.compiler.TypeValue;
+import org.manifold.compiler.Value;
 
 public class LiteralExpression extends Expression {
   private Value value;
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/MultipleAssignmentException.java b/src/main/java/org/manifold/compiler/front/MultipleAssignmentException.java
similarity index 89%
rename from src/main/java/org/manifold/frontend/syntaxtree/MultipleAssignmentException.java
rename to src/main/java/org/manifold/compiler/front/MultipleAssignmentException.java
index 979dc57..f0cb7b0 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/MultipleAssignmentException.java
+++ b/src/main/java/org/manifold/compiler/front/MultipleAssignmentException.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
 public class MultipleAssignmentException extends Exception {
   private static final long serialVersionUID = 1L;
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/MultipleDefinitionException.java b/src/main/java/org/manifold/compiler/front/MultipleDefinitionException.java
similarity index 89%
rename from src/main/java/org/manifold/frontend/syntaxtree/MultipleDefinitionException.java
rename to src/main/java/org/manifold/compiler/front/MultipleDefinitionException.java
index 0df6e97..b68b410 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/MultipleDefinitionException.java
+++ b/src/main/java/org/manifold/compiler/front/MultipleDefinitionException.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
 public class MultipleDefinitionException extends Exception {
   private static final long serialVersionUID = 1L;
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/Namespace.java b/src/main/java/org/manifold/compiler/front/Namespace.java
similarity index 93%
rename from src/main/java/org/manifold/frontend/syntaxtree/Namespace.java
rename to src/main/java/org/manifold/compiler/front/Namespace.java
index 2fb6fb8..ae8b506 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/Namespace.java
+++ b/src/main/java/org/manifold/compiler/front/Namespace.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
 public class Namespace {
   private NamespaceIdentifier absoluteName;
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/NamespaceIdentifier.java b/src/main/java/org/manifold/compiler/front/NamespaceIdentifier.java
similarity index 97%
rename from src/main/java/org/manifold/frontend/syntaxtree/NamespaceIdentifier.java
rename to src/main/java/org/manifold/compiler/front/NamespaceIdentifier.java
index 0bc4e60..7d1c2e5 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/NamespaceIdentifier.java
+++ b/src/main/java/org/manifold/compiler/front/NamespaceIdentifier.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
 import java.util.Arrays;
 import java.util.List;
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/Scope.java b/src/main/java/org/manifold/compiler/front/Scope.java
similarity index 95%
rename from src/main/java/org/manifold/frontend/syntaxtree/Scope.java
rename to src/main/java/org/manifold/compiler/front/Scope.java
index d07c127..5afd449 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/Scope.java
+++ b/src/main/java/org/manifold/compiler/front/Scope.java
@@ -1,5 +1,7 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
+import org.manifold.compiler.Value;
+import org.manifold.compiler.TypeValue;
 import java.util.HashMap;
 import java.util.Map;
 
diff --git a/src/main/java/org/manifold/compiler/front/Statement.java b/src/main/java/org/manifold/compiler/front/Statement.java
new file mode 100644
index 0000000..be6701d
--- /dev/null
+++ b/src/main/java/org/manifold/compiler/front/Statement.java
@@ -0,0 +1,5 @@
+package org.manifold.compiler.front;
+
+public abstract class Statement {
+
+}
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/TypeMismatchException.java b/src/main/java/org/manifold/compiler/front/TypeMismatchException.java
similarity index 81%
rename from src/main/java/org/manifold/frontend/syntaxtree/TypeMismatchException.java
rename to src/main/java/org/manifold/compiler/front/TypeMismatchException.java
index 5f3670b..7069a28 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/TypeMismatchException.java
+++ b/src/main/java/org/manifold/compiler/front/TypeMismatchException.java
@@ -1,4 +1,7 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
+
+import org.manifold.compiler.TypeValue;
+import org.manifold.compiler.Value;
 
 public class TypeMismatchException extends Exception {
   private static final long serialVersionUID = 1L;
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/Variable.java b/src/main/java/org/manifold/compiler/front/Variable.java
similarity index 91%
rename from src/main/java/org/manifold/frontend/syntaxtree/Variable.java
rename to src/main/java/org/manifold/compiler/front/Variable.java
index b83441b..1abffea 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/Variable.java
+++ b/src/main/java/org/manifold/compiler/front/Variable.java
@@ -1,4 +1,8 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
+
+import org.manifold.compiler.TypeValue;
+import org.manifold.compiler.Value;
+import org.manifold.compiler.TypeTypeValue;
 
 public class Variable {
   private final VariableIdentifier identifier;
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/VariableIdentifier.java b/src/main/java/org/manifold/compiler/front/VariableIdentifier.java
similarity index 96%
rename from src/main/java/org/manifold/frontend/syntaxtree/VariableIdentifier.java
rename to src/main/java/org/manifold/compiler/front/VariableIdentifier.java
index c95c1b8..c2f3516 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/VariableIdentifier.java
+++ b/src/main/java/org/manifold/compiler/front/VariableIdentifier.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
 public class VariableIdentifier {
 
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/VariableNotAssignedException.java b/src/main/java/org/manifold/compiler/front/VariableNotAssignedException.java
similarity index 90%
rename from src/main/java/org/manifold/frontend/syntaxtree/VariableNotAssignedException.java
rename to src/main/java/org/manifold/compiler/front/VariableNotAssignedException.java
index 27a16f7..7ac219f 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/VariableNotAssignedException.java
+++ b/src/main/java/org/manifold/compiler/front/VariableNotAssignedException.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
 public class VariableNotAssignedException extends Exception {
   private static final long serialVersionUID = 1L;
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/VariableNotDefinedException.java b/src/main/java/org/manifold/compiler/front/VariableNotDefinedException.java
similarity index 89%
rename from src/main/java/org/manifold/frontend/syntaxtree/VariableNotDefinedException.java
rename to src/main/java/org/manifold/compiler/front/VariableNotDefinedException.java
index 492a7ab..9627c10 100644
--- a/src/main/java/org/manifold/frontend/syntaxtree/VariableNotDefinedException.java
+++ b/src/main/java/org/manifold/compiler/front/VariableNotDefinedException.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
 public class VariableNotDefinedException extends Exception {
   private static final long serialVersionUID = 1L;
diff --git a/src/main/java/org/manifold/intermediate/Schematic.java b/src/main/java/org/manifold/compiler/middle/Schematic.java
similarity index 75%
rename from src/main/java/org/manifold/intermediate/Schematic.java
rename to src/main/java/org/manifold/compiler/middle/Schematic.java
index cf3c252..d35a430 100644
--- a/src/main/java/org/manifold/intermediate/Schematic.java
+++ b/src/main/java/org/manifold/compiler/middle/Schematic.java
@@ -1,5 +1,20 @@
-package org.manifold.intermediate;
+package org.manifold.compiler.middle;
 
+import org.manifold.compiler.MultipleDefinitionException;
+import org.manifold.compiler.StringTypeValue;
+import org.manifold.compiler.MultipleAssignmentException;
+import org.manifold.compiler.NodeValue;
+import org.manifold.compiler.ConnectionValue;
+import org.manifold.compiler.ConnectionType;
+import org.manifold.compiler.NodeTypeValue;
+import org.manifold.compiler.PortTypeValue;
+import org.manifold.compiler.TypeValue;
+import org.manifold.compiler.UndeclaredIdentifierException;
+import org.manifold.compiler.ConstraintType;
+import org.manifold.compiler.ConstraintValue;
+import org.manifold.compiler.UndefinedBehaviourError;
+import org.manifold.compiler.BooleanTypeValue;
+import org.manifold.compiler.IntegerTypeValue;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 
@@ -19,18 +34,18 @@ public class Schematic {
   
   // Maps containing object definitions for this schematic; they are all
   // indexed by the (string) type-name of the object.
-  private final Map<String, Type> userDefinedTypes;
-  private final Map<String, PortType> portTypes;
-  private final Map<String, NodeType> nodeTypes;
+  private final Map<String, TypeValue> userDefinedTypes;
+  private final Map<String, PortTypeValue> portTypes;
+  private final Map<String, NodeTypeValue> nodeTypes;
   private final Map<String, ConnectionType> connectionTypes;
   private final Map<String, ConstraintType> constraintTypes;
   
   // Maps containing instantiated objects for this schematic; they are all
   // indexed by the (string) instance-name of the object.
-  private final Map<String, Node> nodes;
-  private final Map<Node, String> reverseNodeMap;
-  private final Map<String, Connection> connections;
-  private final Map<String, Constraint> constraints;
+  private final Map<String, NodeValue> nodes;
+  private final Map<NodeValue, String> reverseNodeMap;
+  private final Map<String, ConnectionValue> connections;
+  private final Map<String, ConstraintValue> constraints;
 
   public Schematic(String name) {
     this.name = name;
@@ -55,9 +70,9 @@ public Schematic(String name) {
    * represented in here.
    */
   private void populateDefaultType(){
-    Type boolType = BooleanType.getInstance();
-    Type intType = IntegerType.getInstance();
-    Type stringType = StringType.getInstance();
+    TypeValue boolType = BooleanTypeValue.getInstance();
+    TypeValue intType = IntegerTypeValue.getInstance();
+    TypeValue stringType = StringTypeValue.getInstance();
     
     try {
       addUserDefinedType("Bool", boolType);
@@ -72,7 +87,7 @@ private void populateDefaultType(){
     }
   }
   
-  public void addUserDefinedType(String typename, Type td)
+  public void addUserDefinedType(String typename, TypeValue td)
       throws MultipleDefinitionException{
     if (userDefinedTypes.containsKey(typename)){
       throw new MultipleDefinitionException("type-definition", typename);
@@ -80,7 +95,7 @@ public void addUserDefinedType(String typename, Type td)
     userDefinedTypes.put(typename, td);
   }
   
-  public Type getUserDefinedType(String typename)
+  public TypeValue getUserDefinedType(String typename)
       throws UndeclaredIdentifierException {
     if (userDefinedTypes.containsKey(typename)) {
       return userDefinedTypes.get(typename);
@@ -89,7 +104,7 @@ public Type getUserDefinedType(String typename)
     }
   }
   
-  public void addPortType(String typename, PortType portType)
+  public void addPortType(String typename, PortTypeValue portType)
       throws MultipleDefinitionException{
     if (portTypes.containsKey(typename)) {
       throw new MultipleDefinitionException("port-definition", typename);
@@ -97,7 +112,7 @@ public void addPortType(String typename, PortType portType)
     portTypes.put(typename, portType);
   }
   
-  public PortType getPortType(String typename)
+  public PortTypeValue getPortType(String typename)
       throws UndeclaredIdentifierException {
     if (portTypes.containsKey(typename)) {
       return portTypes.get(typename);
@@ -106,7 +121,7 @@ public PortType getPortType(String typename)
     }
   }
   
-  public void addNodeType(String typename, NodeType nd)
+  public void addNodeType(String typename, NodeTypeValue nd)
       throws MultipleDefinitionException{
     if (nodeTypes.containsKey(typename)) {
       throw new MultipleDefinitionException("node-definition", typename);
@@ -114,7 +129,7 @@ public void addNodeType(String typename, NodeType nd)
     nodeTypes.put(typename, nd);
   }
   
-  public NodeType getNodeType(String typename)
+  public NodeTypeValue getNodeType(String typename)
       throws UndeclaredIdentifierException {
     
     if (nodeTypes.containsKey(typename)){
@@ -158,7 +173,7 @@ public ConstraintType getConstraintType(String typename)
     }
   }
   
-  public void addNode(String instanceName, Node node)
+  public void addNode(String instanceName, NodeValue node)
       throws MultipleAssignmentException {
     if (nodes.containsKey(instanceName) || reverseNodeMap.containsKey(node)) {
       throw new MultipleAssignmentException("node", instanceName);
@@ -167,7 +182,7 @@ public void addNode(String instanceName, Node node)
     reverseNodeMap.put(node, instanceName);
   }
   
-  public Node getNode(String instanceName)
+  public NodeValue getNode(String instanceName)
       throws UndeclaredIdentifierException {
     if (nodes.containsKey(instanceName)){
       return nodes.get(instanceName);
@@ -176,14 +191,14 @@ public Node getNode(String instanceName)
     }
   }
   
-  public String getNodeName(Node instance) {
+  public String getNodeName(NodeValue instance) {
     if (reverseNodeMap.containsKey(instance)) {
       return reverseNodeMap.get(instance);
     }
     throw new NoSuchElementException();
   }
   
-  public void addConnection(String instanceName, Connection conn)
+  public void addConnection(String instanceName, ConnectionValue conn)
       throws MultipleAssignmentException {
     if (connections.containsKey(instanceName)) {
       throw new MultipleAssignmentException("connection", instanceName);
@@ -191,7 +206,7 @@ public void addConnection(String instanceName, Connection conn)
     connections.put(instanceName, conn);
   }
   
-  public Connection getConnection(String instanceName)
+  public ConnectionValue getConnection(String instanceName)
       throws UndeclaredIdentifierException {
     if (connections.containsKey(instanceName)){
       return connections.get(instanceName);
@@ -200,7 +215,7 @@ public Connection getConnection(String instanceName)
     }
   }
   
-  public void addConstraint(String instanceName, Constraint constraint)
+  public void addConstraint(String instanceName, ConstraintValue constraint)
       throws MultipleAssignmentException {
     if (constraints.containsKey(instanceName)){
       throw new MultipleAssignmentException("constraint", instanceName);
@@ -208,7 +223,7 @@ public void addConstraint(String instanceName, Constraint constraint)
     constraints.put(instanceName, constraint);
   }
   
-  public Constraint getConstraint(String instanceName)
+  public ConstraintValue getConstraint(String instanceName)
       throws UndeclaredIdentifierException {
     if (constraints.containsKey(instanceName)){
       return constraints.get(instanceName);
diff --git a/src/main/java/org/manifold/intermediate/SchematicException.java b/src/main/java/org/manifold/compiler/middle/SchematicException.java
similarity index 89%
rename from src/main/java/org/manifold/intermediate/SchematicException.java
rename to src/main/java/org/manifold/compiler/middle/SchematicException.java
index 491e899..0931aed 100644
--- a/src/main/java/org/manifold/intermediate/SchematicException.java
+++ b/src/main/java/org/manifold/compiler/middle/SchematicException.java
@@ -1,4 +1,4 @@
-package org.manifold.intermediate;
+package org.manifold.compiler.middle;
 
 /**
  * Base class for errors caused by the data from the Schematic being invalid.
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/BitTypeValue.java b/src/main/java/org/manifold/frontend/syntaxtree/BitTypeValue.java
deleted file mode 100644
index 254e846..0000000
--- a/src/main/java/org/manifold/frontend/syntaxtree/BitTypeValue.java
+++ /dev/null
@@ -1,14 +0,0 @@
-package org.manifold.frontend.syntaxtree;
-
-public class BitTypeValue extends TypeValue {
-
-  private static final BitTypeValue instance = new BitTypeValue();
-
-  public static BitTypeValue getInstance() {
-    return instance;
-  }
-
-  private BitTypeValue() { }
-
-  public void verify() { }
-}
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/Statement.java b/src/main/java/org/manifold/frontend/syntaxtree/Statement.java
deleted file mode 100644
index 1cfbbfe..0000000
--- a/src/main/java/org/manifold/frontend/syntaxtree/Statement.java
+++ /dev/null
@@ -1,5 +0,0 @@
-package org.manifold.frontend.syntaxtree;
-
-public abstract class Statement {
-
-}
diff --git a/src/main/java/org/manifold/frontend/syntaxtree/TypeTypeValue.java b/src/main/java/org/manifold/frontend/syntaxtree/TypeTypeValue.java
deleted file mode 100644
index 86927d4..0000000
--- a/src/main/java/org/manifold/frontend/syntaxtree/TypeTypeValue.java
+++ /dev/null
@@ -1,24 +0,0 @@
-package org.manifold.frontend.syntaxtree;
-
-public class TypeTypeValue extends TypeValue {
-
-  private static final TypeTypeValue instance = new TypeTypeValue();
-
-  public static TypeTypeValue getInstance(){
-    return instance;
-  }
-
-  private TypeTypeValue() { }
-
-  public TypeTypeValue getType() {
-    return instance;
-  }
-
-  public void verify() { }
-
-  // We override the isSubtypeOf method to prevent recursive loops.
-  @Override
-  public boolean isSubtypeOf(TypeValue type) {
-    return this == type;
-  }
-}
diff --git a/src/main/java/org/manifold/intermediate/ArrayType.java b/src/main/java/org/manifold/intermediate/ArrayType.java
deleted file mode 100644
index e98d4d9..0000000
--- a/src/main/java/org/manifold/intermediate/ArrayType.java
+++ /dev/null
@@ -1,14 +0,0 @@
-package org.manifold.intermediate;
-
-
-public class ArrayType extends Type {
-  private Type elementType;
-  public Type getElementType(){
-    return this.elementType;
-  }
-  
-  public ArrayType(Type elementType){
-    this.elementType = elementType;
-  }
- 
-}
diff --git a/src/main/java/org/manifold/intermediate/ArrayValue.java b/src/main/java/org/manifold/intermediate/ArrayValue.java
deleted file mode 100644
index 340ec8c..0000000
--- a/src/main/java/org/manifold/intermediate/ArrayValue.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package org.manifold.intermediate;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class ArrayValue extends Value {
-
-  private final Type elementType;
-  private List<Value> contents = null;
-
-  public ArrayValue(ArrayType t, List<Value> contents)
-      throws TypeMismatchException {
-    super(t);
-    this.elementType = t.getElementType();
-    // type-check contents -- every Value must have type 'elementType'
-    for (Value v : contents){
-      Type vt = v.getType();
-      if (!vt.equals(elementType)){
-        throw new TypeMismatchException(elementType, vt);
-      }
-    }
-    // now we can copy the new list into our object
-    this.contents = new ArrayList<Value>(contents);
-  }
-
-  public Type getElementType(){
-    return this.elementType;
-  }
-
-  public Value get(Integer i){
-    return contents.get(i);
-  }
-
-  public Integer length(){
-    return contents.size();
-  }
-
-}
diff --git a/src/main/java/org/manifold/intermediate/BooleanType.java b/src/main/java/org/manifold/intermediate/BooleanType.java
deleted file mode 100644
index b6c0104..0000000
--- a/src/main/java/org/manifold/intermediate/BooleanType.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package org.manifold.intermediate;
-
-public class BooleanType extends Type {
-  private static final BooleanType instance = new BooleanType();
-
-  private BooleanType() {
-
-  }
-
-  public static BooleanType getInstance() {
-    return instance;
-  }
-}
diff --git a/src/main/java/org/manifold/intermediate/BooleanValue.java b/src/main/java/org/manifold/intermediate/BooleanValue.java
deleted file mode 100644
index e91fd3b..0000000
--- a/src/main/java/org/manifold/intermediate/BooleanValue.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package org.manifold.intermediate;
-
-public class BooleanValue extends Value {
-
-  private final Boolean val;
-  public BooleanValue(Type t, Boolean val){
-    super(t);
-    this.val = val;
-  }
-
-}
diff --git a/src/main/java/org/manifold/intermediate/ConnectionType.java b/src/main/java/org/manifold/intermediate/ConnectionType.java
deleted file mode 100644
index bf615fd..0000000
--- a/src/main/java/org/manifold/intermediate/ConnectionType.java
+++ /dev/null
@@ -1,18 +0,0 @@
-package org.manifold.intermediate;
-
-import com.google.common.collect.ImmutableMap;
-
-import java.util.Map;
-
-
-public class ConnectionType extends Type {
-  private final ImmutableMap<String, Type> attributes;
-  
-  public ConnectionType(Map<String, Type> attributes){
-    this.attributes = ImmutableMap.copyOf(attributes);
-  }
-  
-  public ImmutableMap<String, Type> getAttributes() {
-    return attributes;
-  }
-}
diff --git a/src/main/java/org/manifold/intermediate/ConstraintType.java b/src/main/java/org/manifold/intermediate/ConstraintType.java
deleted file mode 100644
index 2dbbf43..0000000
--- a/src/main/java/org/manifold/intermediate/ConstraintType.java
+++ /dev/null
@@ -1,18 +0,0 @@
-package org.manifold.intermediate;
-
-import com.google.common.collect.ImmutableMap;
-
-import java.util.Map;
-
-
-public class ConstraintType extends Type {
-  private final ImmutableMap<String, Type> attributes;
-  
-  public ConstraintType(Map<String, Type> attributes){
-    this.attributes = ImmutableMap.copyOf(attributes);
-  }
-  
-  public ImmutableMap<String, Type> getAttributes() {
-    return attributes;
-  }
-}
diff --git a/src/main/java/org/manifold/intermediate/IntegerType.java b/src/main/java/org/manifold/intermediate/IntegerType.java
deleted file mode 100644
index d0cd164..0000000
--- a/src/main/java/org/manifold/intermediate/IntegerType.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package org.manifold.intermediate;
-
-public class IntegerType extends Type {
-  private static final IntegerType instance = new IntegerType();
-
-  private IntegerType() {
-
-  }
-
-  public static IntegerType getInstance() {
-    return instance;
-  }
-}
diff --git a/src/main/java/org/manifold/intermediate/IntegerValue.java b/src/main/java/org/manifold/intermediate/IntegerValue.java
deleted file mode 100644
index 8e58c07..0000000
--- a/src/main/java/org/manifold/intermediate/IntegerValue.java
+++ /dev/null
@@ -1,12 +0,0 @@
-package org.manifold.intermediate;
-
-
-public class IntegerValue extends Value {
-
-  private final Integer val;
-  public IntegerValue(Type t, Integer val){
-    super(t);
-    this.val = val;
-  }
-  
-}
diff --git a/src/main/java/org/manifold/intermediate/NodeType.java b/src/main/java/org/manifold/intermediate/NodeType.java
deleted file mode 100644
index 6a94710..0000000
--- a/src/main/java/org/manifold/intermediate/NodeType.java
+++ /dev/null
@@ -1,24 +0,0 @@
-package org.manifold.intermediate;
-
-import com.google.common.collect.ImmutableMap;
-
-import java.util.Map;
-
-public class NodeType extends Type {
-
-  private final Map<String, Type> attributes;
-  private final Map<String, PortType> ports;
-
-  public NodeType(Map<String, Type> attributes, Map<String, PortType> ports) {
-    this.attributes = ImmutableMap.copyOf(attributes);
-    this.ports = ImmutableMap.copyOf(ports);
-  }
-  
-  public Map<String, Type> getAttributes() {
-    return this.attributes;
-  }
-
-  public Map<String, PortType> getPorts() {
-    return this.ports;
-  }
-}
diff --git a/src/main/java/org/manifold/intermediate/Port.java b/src/main/java/org/manifold/intermediate/Port.java
deleted file mode 100644
index 94aed38..0000000
--- a/src/main/java/org/manifold/intermediate/Port.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package org.manifold.intermediate;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import java.util.Map;
-
-public class Port extends Value {
-
-  private final Attributes attributes;
-  private final Node parent;
-
-  public Value getAttribute(String attrName)
-      throws UndeclaredAttributeException {
-    return attributes.get(attrName);
-  }
-
-  public Node getParent() {
-    return parent;
-  }
-
-  public Port(PortType type, Node parent, Map<String, Value> attrMap)
-      throws UndeclaredAttributeException, InvalidAttributeException {
-    super(type);
-    this.attributes = new Attributes(type.getAttributes(), attrMap);
-    this.parent = checkNotNull(parent);
-  }
-}
diff --git a/src/main/java/org/manifold/intermediate/PortType.java b/src/main/java/org/manifold/intermediate/PortType.java
deleted file mode 100644
index 2257a8c..0000000
--- a/src/main/java/org/manifold/intermediate/PortType.java
+++ /dev/null
@@ -1,16 +0,0 @@
-package org.manifold.intermediate;
-
-import com.google.common.collect.ImmutableMap;
-import java.util.Map;
-
-public class PortType extends Type {
-  private final Map<String, Type> attributes;
-  
-  public PortType(Map<String, Type> attributes){
-    this.attributes = ImmutableMap.copyOf(attributes);
-  }
-  
-  public Map<String, Type> getAttributes() {
-    return this.attributes;
-  }
-}
diff --git a/src/main/java/org/manifold/intermediate/StringType.java b/src/main/java/org/manifold/intermediate/StringType.java
deleted file mode 100644
index 480c152..0000000
--- a/src/main/java/org/manifold/intermediate/StringType.java
+++ /dev/null
@@ -1,12 +0,0 @@
-package org.manifold.intermediate;
-
-public class StringType extends Type {
-
-  private static final StringType instance = new StringType();
-
-  private StringType() { }
-
-  public static StringType getInstance() {
-    return instance;
-  }
-}
diff --git a/src/main/java/org/manifold/intermediate/StringValue.java b/src/main/java/org/manifold/intermediate/StringValue.java
deleted file mode 100644
index 5601bf3..0000000
--- a/src/main/java/org/manifold/intermediate/StringValue.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package org.manifold.intermediate;
-
-
-public class StringValue extends Value {
-
-  private final String val;
-
-  public StringValue(Type t, String val) {
-    super(t);
-    this.val = val;
-  }
-
-}
diff --git a/src/main/java/org/manifold/intermediate/Type.java b/src/main/java/org/manifold/intermediate/Type.java
deleted file mode 100644
index 368ddba..0000000
--- a/src/main/java/org/manifold/intermediate/Type.java
+++ /dev/null
@@ -1,12 +0,0 @@
-package org.manifold.intermediate;
-
-public abstract class Type {
-  
-  @Override
-  public boolean equals(Object other){
-    // Every value of the same type references the same type object;
-    // therefore the following comparison is exactly what we need.
-    return (this == other);
-  }
-  
-}
diff --git a/src/main/java/org/manifold/intermediate/Value.java b/src/main/java/org/manifold/intermediate/Value.java
deleted file mode 100644
index 3a366b2..0000000
--- a/src/main/java/org/manifold/intermediate/Value.java
+++ /dev/null
@@ -1,16 +0,0 @@
-package org.manifold.intermediate;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-public abstract class Value {
-  
-  private Type type = null;
-  
-  public Type getType(){
-    return type;
-  }
-  
-  public Value(Type type){
-    this.type = checkNotNull(type);
-  }
-}
diff --git a/src/test/java/org/manifold/intermediate/TestArrayType.java b/src/test/java/org/manifold/compiler/TestArrayType.java
similarity index 52%
rename from src/test/java/org/manifold/intermediate/TestArrayType.java
rename to src/test/java/org/manifold/compiler/TestArrayType.java
index d362f8a..87ae7cb 100644
--- a/src/test/java/org/manifold/intermediate/TestArrayType.java
+++ b/src/test/java/org/manifold/compiler/TestArrayType.java
@@ -1,4 +1,4 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
 
 import static org.junit.Assert.*;
 
@@ -8,12 +8,14 @@ public class TestArrayType {
 
   @Test
   public void testGetElementType() {
-    Type elementType = BooleanType.getInstance();
-    ArrayType aType = new ArrayType(elementType);
+    TypeValue elementType = BooleanTypeValue.getInstance();
+    
+    ArrayTypeValue arrayType = new ArrayTypeValue(elementType);
+    
     assertEquals(
         "element type not Boolean",
         elementType,
-        aType.getElementType()
+        arrayType.getElementType()
     );
   }
 
diff --git a/src/test/java/org/manifold/intermediate/TestAtomicTypes.java b/src/test/java/org/manifold/compiler/TestAtomicTypes.java
similarity index 53%
rename from src/test/java/org/manifold/intermediate/TestAtomicTypes.java
rename to src/test/java/org/manifold/compiler/TestAtomicTypes.java
index b44d4a6..d7f36f2 100644
--- a/src/test/java/org/manifold/intermediate/TestAtomicTypes.java
+++ b/src/test/java/org/manifold/compiler/TestAtomicTypes.java
@@ -1,4 +1,4 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
 
 import static org.junit.Assert.*;
 
@@ -8,14 +8,14 @@ public class TestAtomicTypes {
   
   @Test
   public void testEquality() {
-    BooleanType p1 = BooleanType.getInstance();
-    IntegerType p2 = IntegerType.getInstance();
-    StringType p3 = StringType.getInstance();
+    BooleanTypeValue p1 = BooleanTypeValue.getInstance();
+    IntegerTypeValue p2 = IntegerTypeValue.getInstance();
+    StringTypeValue p3 = StringTypeValue.getInstance();
     
     // Primitive types are singletons.
-    assertEquals(p1, BooleanType.getInstance());
-    assertEquals(p2, IntegerType.getInstance());
-    assertEquals(p3, StringType.getInstance());
+    assertEquals(p1, BooleanTypeValue.getInstance());
+    assertEquals(p2, IntegerTypeValue.getInstance());
+    assertEquals(p3, StringTypeValue.getInstance());
     
     // Two types are equal iff they are the same object
     assertNotEquals(p1, p2);
diff --git a/src/test/java/org/manifold/compiler/TestBooleanTypeValue.java b/src/test/java/org/manifold/compiler/TestBooleanTypeValue.java
new file mode 100644
index 0000000..eb69ada
--- /dev/null
+++ b/src/test/java/org/manifold/compiler/TestBooleanTypeValue.java
@@ -0,0 +1,28 @@
+package org.manifold.compiler;
+
+import static org.hamcrest.CoreMatchers.instanceOf;
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+public class TestBooleanTypeValue {
+
+  private BooleanTypeValue getInstance() {
+    return BooleanTypeValue.getInstance();
+  }
+  
+  @Test
+  public void testStaticGetInstance() {
+    assertThat(
+      BooleanTypeValue.getInstance(),
+      instanceOf(BooleanTypeValue.class)
+    );
+  }
+  
+  @Test
+  public void testVerify() throws Exception {
+    getInstance().verify();
+  }
+
+
+}
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestBitValue.java b/src/test/java/org/manifold/compiler/TestBooleanValue.java
similarity index 65%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestBitValue.java
rename to src/test/java/org/manifold/compiler/TestBooleanValue.java
index 058cd08..52f3dfc 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestBitValue.java
+++ b/src/test/java/org/manifold/compiler/TestBooleanValue.java
@@ -1,20 +1,20 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler;
 
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.junit.Assert.*;
 
 import org.junit.Test;
 
-public class TestBitValue {
+public class TestBooleanValue {
   
-  private BitValue getInstance(boolean value) {
-    return BitValue.getInstance(value);
+  private BooleanValue getInstance(boolean value) {
+    return BooleanValue.getInstance(value);
   }
 
   @Test
   public void testStaticGetInstance() {
-    assertThat(BitValue.getInstance(true), instanceOf(BitValue.class));
-    assertThat(BitValue.getInstance(false), instanceOf(BitValue.class));
+    assertThat(BooleanValue.getInstance(true), instanceOf(BooleanValue.class));
+    assertThat(BooleanValue.getInstance(false), instanceOf(BooleanValue.class));
   }
 
   @Test
@@ -27,11 +27,11 @@ public void testToBoolean() {
   public void testGetType() {
     assertThat(
       getInstance(true).getType(),
-      instanceOf(BitTypeValue.class)
+      instanceOf(BooleanTypeValue.class)
     );
     assertThat(
       getInstance(false).getType(),
-      instanceOf(BitTypeValue.class)
+      instanceOf(BooleanTypeValue.class)
     );
   }
   
diff --git a/src/test/java/org/manifold/intermediate/TestConnection.java b/src/test/java/org/manifold/compiler/TestConnection.java
similarity index 59%
rename from src/test/java/org/manifold/intermediate/TestConnection.java
rename to src/test/java/org/manifold/compiler/TestConnection.java
index 1eb9d99..e2376e3 100644
--- a/src/test/java/org/manifold/intermediate/TestConnection.java
+++ b/src/test/java/org/manifold/compiler/TestConnection.java
@@ -1,4 +1,4 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
 
 import static org.junit.Assert.assertEquals;
 
@@ -9,42 +9,47 @@
 
 import java.util.HashMap;
 import java.util.Map;
+import org.manifold.compiler.middle.SchematicException;
 
 
 public class TestConnection {
-  private static final PortType defaultPortDefinition =
-      new PortType(new HashMap<>());
-  private static final Type boolType = BooleanType.getInstance();
+  private static final PortTypeValue defaultPortDefinition =
+      new PortTypeValue(new HashMap<>());
+  private static final TypeValue boolType = BooleanTypeValue.getInstance();
   private static final String PORT_NAME1 = "testport";
   private static final String PORT_NAME2 = "another port";
   
-  private NodeType nType;
-  private Node n;
+  private NodeTypeValue nType;
+  private NodeValue n;
   private ConnectionType conType;
-  private Connection ept;
+  private ConnectionValue ept;
   private Value v;
   
   @Before
   public void setup() throws SchematicException {
-    Map<String, PortType> portMap = ImmutableMap.of(
+    Map<String, PortTypeValue> portMap = ImmutableMap.of(
         PORT_NAME1, defaultPortDefinition,
         PORT_NAME2, defaultPortDefinition);
     Map<String, Map<String, Value>> portAttrMap = ImmutableMap.of(
         PORT_NAME1, ImmutableMap.of(),
         PORT_NAME2, ImmutableMap.of());
-    nType = new NodeType(new HashMap<>(), portMap);
-    n = new Node(nType, new HashMap<>(), portAttrMap);
-    v = new BooleanValue(boolType, true);
+    nType = new NodeTypeValue(new HashMap<>(), portMap);
+    n = new NodeValue(nType, new HashMap<>(), portAttrMap);
+    v = BooleanValue.getInstance(true);
     conType = new ConnectionType(ImmutableMap.of("v", boolType));
     
-    ept = new Connection(conType, n.getPort(PORT_NAME1), n.getPort(PORT_NAME2),
-        ImmutableMap.of("v", v));
+    ept = new ConnectionValue(
+        conType,
+        n.getPort(PORT_NAME1),
+        n.getPort(PORT_NAME2),
+        ImmutableMap.of("v", v)
+    );
   }
 
   @Test(expected = UndefinedBehaviourError.class)
   public void testIncorrectPortConnection() throws SchematicException {
     
-    new Connection(
+    new ConnectionValue(
       conType,
       n.getPort(PORT_NAME1),
       n.getPort(PORT_NAME1),
@@ -57,22 +62,22 @@ public void testGetAttribute() throws UndeclaredAttributeException {
     assertEquals(v, ept.getAttribute("v"));
   }
 
-  @Test(expected = org.manifold.intermediate.UndeclaredAttributeException.class)
+  @Test(expected = org.manifold.compiler.UndeclaredAttributeException.class)
   public void testGetAttribute_nonexistent()
       throws UndeclaredAttributeException {
     ept.getAttribute("bogus");
   }
 
-  @Test(expected = org.manifold.intermediate.UndeclaredAttributeException.class)
+  @Test(expected = org.manifold.compiler.UndeclaredAttributeException.class)
   public void testCreateWithUndeclaredAttribute() throws SchematicException {
-    new Connection(conType, n.getPort(PORT_NAME1), n.getPort(PORT_NAME2),
+    new ConnectionValue(conType, n.getPort(PORT_NAME1), n.getPort(PORT_NAME2),
         ImmutableMap.of());
   }
 
-  @Test(expected = org.manifold.intermediate.InvalidAttributeException.class)
+  @Test(expected = org.manifold.compiler.InvalidAttributeException.class)
   public void testCreateWithInvalidAttribute() throws SchematicException {
-    Value v = new BooleanValue(boolType, true);
-    new Connection(conType, n.getPort(PORT_NAME1), n.getPort(PORT_NAME2), 
+    Value v = BooleanValue.getInstance(true);
+    new ConnectionValue(conType, n.getPort(PORT_NAME1), n.getPort(PORT_NAME2), 
         ImmutableMap.of("v", v, "bogus", v));
   }
   
diff --git a/src/test/java/org/manifold/compiler/TestConstraint.java b/src/test/java/org/manifold/compiler/TestConstraint.java
new file mode 100644
index 0000000..d3b8bf9
--- /dev/null
+++ b/src/test/java/org/manifold/compiler/TestConstraint.java
@@ -0,0 +1,44 @@
+package org.manifold.compiler;
+
+import static org.junit.Assert.assertEquals;
+
+import com.google.common.collect.ImmutableMap;
+
+import org.junit.Test;
+import org.manifold.compiler.middle.SchematicException;
+
+public class TestConstraint {
+
+  private static final TypeValue boolType = BooleanTypeValue.getInstance();
+  private static final ConstraintType defaultConstraintDefinition =
+      new ConstraintType(ImmutableMap.of("v", boolType));
+
+  @Test
+  public void testGetAttribute() throws SchematicException {
+    Value v = BooleanValue.getInstance(true);
+    ConstraintValue ept = new ConstraintValue(defaultConstraintDefinition,
+        ImmutableMap.of("v", v));
+    Value vActual = ept.getAttribute("v");
+    assertEquals(v, vActual);
+  }
+
+  @Test(expected = org.manifold.compiler.UndeclaredAttributeException.class)
+  public void testGetAttribute_nonexistent() throws SchematicException {
+    Value v = BooleanValue.getInstance(true);
+    ConstraintValue ept = new ConstraintValue(defaultConstraintDefinition,
+        ImmutableMap.of("v", v));
+    ept.getAttribute("bogus");
+  }
+
+  @Test(expected = org.manifold.compiler.UndeclaredAttributeException.class)
+  public void testMissingAttribute() throws SchematicException {
+    new ConstraintValue(defaultConstraintDefinition, ImmutableMap.of());
+  }
+
+  @Test(expected = org.manifold.compiler.InvalidAttributeException.class)
+  public void testExtraAttribute() throws Exception {
+    Value v = BooleanValue.getInstance(true);
+    new ConstraintValue(defaultConstraintDefinition,
+        ImmutableMap.of("v", v, "vBogus", v));
+  }
+}
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestEnumTypeValue.java b/src/test/java/org/manifold/compiler/TestEnumTypeValue.java
similarity index 64%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestEnumTypeValue.java
rename to src/test/java/org/manifold/compiler/TestEnumTypeValue.java
index 24620c6..854c409 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestEnumTypeValue.java
+++ b/src/test/java/org/manifold/compiler/TestEnumTypeValue.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler;
 
 import static org.junit.Assert.*;
 
@@ -7,6 +7,10 @@
 
 import java.util.HashMap;
 import java.util.Set;
+import org.manifold.compiler.front.EnumIdentifierNotDefined;
+import org.manifold.compiler.front.EnumTypeValue;
+import org.manifold.compiler.front.EnumValue;
+import org.manifold.compiler.front.TypeMismatchException;
 
 public class TestEnumTypeValue {
 
@@ -15,8 +19,8 @@ public class TestEnumTypeValue {
   @Before
   public void setup() {
     enumMap.clear();
-    enumMap.put("foo", BitValue.getInstance(true));
-    enumMap.put("bar", BitValue.getInstance(false));
+    enumMap.put("foo", BooleanValue.getInstance(true));
+    enumMap.put("bar", BooleanValue.getInstance(false));
   }
 
   @Test(expected = TypeMismatchException.class)
@@ -28,7 +32,7 @@ public void testIncorrectType() throws Exception {
   @Test(expected = EnumIdentifierNotDefined.class)
   public void testIncorrectIdentifier() throws Exception {
     EnumTypeValue enumType = new EnumTypeValue(
-      BitTypeValue.getInstance(),
+      BooleanTypeValue.getInstance(),
       enumMap
     );
     enumType.verify();
@@ -38,11 +42,11 @@ public void testIncorrectIdentifier() throws Exception {
   @Test
   public void testGetters() throws TypeMismatchException {
     EnumTypeValue enumType = new EnumTypeValue(
-      BitTypeValue.getInstance(),
+      BooleanTypeValue.getInstance(),
       enumMap
     );
     Set<String> enumNames = enumType.getIdentifiers();
     assertTrue(enumNames.containsAll(enumMap.keySet()));
-    assertEquals(BitTypeValue.getInstance(), enumType.getEnumsType());
+    assertEquals(BooleanTypeValue.getInstance(), enumType.getEnumsType());
   }
 }
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestEnumValue.java b/src/test/java/org/manifold/compiler/TestEnumValue.java
similarity index 56%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestEnumValue.java
rename to src/test/java/org/manifold/compiler/TestEnumValue.java
index 26dba8f..d2968cd 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestEnumValue.java
+++ b/src/test/java/org/manifold/compiler/TestEnumValue.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotEquals;
@@ -7,6 +7,10 @@
 import org.junit.Test;
 
 import java.util.HashMap;
+import org.manifold.compiler.front.EnumIdentifierNotDefined;
+import org.manifold.compiler.front.EnumTypeValue;
+import org.manifold.compiler.front.EnumValue;
+import org.manifold.compiler.front.TypeMismatchException;
 
 public class TestEnumValue {
 
@@ -15,14 +19,17 @@ public class TestEnumValue {
   @Before
   public void setup() {
     enumMap.clear();
-    enumMap.put("foo", BitValue.getInstance(true));
-    enumMap.put("bar", BitValue.getInstance(false));
+    enumMap.put("foo", BooleanValue.getInstance(true));
+    enumMap.put("bar", BooleanValue.getInstance(false));
   }
 
   @Test
   public void testGetters()
       throws TypeMismatchException, EnumIdentifierNotDefined {
-    EnumTypeValue type = new EnumTypeValue(BitTypeValue.getInstance(), enumMap);
+    EnumTypeValue type = new EnumTypeValue(
+        BooleanTypeValue.getInstance(),
+        enumMap
+    );
     EnumValue foo1 = new EnumValue(type, "foo");
     assertEquals("foo", foo1.getIdentifier());
     assertEquals(type, foo1.getType());
@@ -30,7 +37,10 @@ public void testGetters()
 
   @Test
   public void testValueInheritedMethods() throws Exception {
-    EnumTypeValue type = new EnumTypeValue(BitTypeValue.getInstance(), enumMap);
+    EnumTypeValue type = new EnumTypeValue(
+        BooleanTypeValue.getInstance(),
+        enumMap
+    );
     EnumValue foo1 = new EnumValue(type, "foo");
     foo1.verify();
     assertEquals(
@@ -43,12 +53,15 @@ public void testValueInheritedMethods() throws Exception {
   @Test
   public void testEnumEquality()
       throws TypeMismatchException, EnumIdentifierNotDefined {
-    EnumTypeValue type = new EnumTypeValue(BitTypeValue.getInstance(), enumMap);
+    EnumTypeValue type = new EnumTypeValue(
+        BooleanTypeValue.getInstance(),
+        enumMap
+    );
     EnumValue foo1 = new EnumValue(type, "foo");
     EnumValue foo2 = new EnumValue(type, "foo");
 
     assertEquals(foo1, foo2);
-    assertEquals(foo1, BitValue.getInstance(true));
-    assertNotEquals(foo1, BitValue.getInstance(false));
+    assertEquals(foo1, BooleanValue.getInstance(true));
+    assertNotEquals(foo1, BooleanValue.getInstance(false));
   }
 }
diff --git a/src/test/java/org/manifold/compiler/TestNode.java b/src/test/java/org/manifold/compiler/TestNode.java
new file mode 100644
index 0000000..4732eb4
--- /dev/null
+++ b/src/test/java/org/manifold/compiler/TestNode.java
@@ -0,0 +1,101 @@
+package org.manifold.compiler;
+
+import static org.junit.Assert.assertEquals;
+
+import com.google.common.collect.ImmutableMap;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+import org.manifold.compiler.middle.SchematicException;
+
+public class TestNode {
+
+  private static final PortTypeValue defaultPortDefinition =
+      new PortTypeValue(new HashMap<>());
+  private static final TypeValue boolType = BooleanTypeValue.getInstance();
+  private static final String PORT_NAME = "testport";
+  private static final String PORT_ATTR_KEY = "the truth will set you free";
+  private static final Map<String, Map<String, Value>> PORT_ATTRS =
+      ImmutableMap.of(PORT_NAME, ImmutableMap.of());
+  
+  private NodeTypeValue hasNoAttrs;
+  private NodeTypeValue hasABCNodeAttr;
+  
+  @Before
+  public void setup() {
+    Map<String, PortTypeValue> portMap =
+        ImmutableMap.of(PORT_NAME, defaultPortDefinition);
+    hasNoAttrs = new NodeTypeValue(new HashMap<>(), portMap);
+    hasABCNodeAttr = new NodeTypeValue(
+        ImmutableMap.of("abc", boolType),
+        portMap
+    );
+  }
+
+  @Test(
+      expected = org.manifold.compiler.InvalidIdentifierException.class)
+  public void testCreateWithMissingPort() throws SchematicException {
+    Value v = BooleanValue.getInstance(true);
+    new NodeValue(hasABCNodeAttr, ImmutableMap.of("abc", v), new HashMap<>());
+  }
+  
+  @Test(
+      expected = org.manifold.compiler.UndeclaredIdentifierException.class)
+  public void testCreateWithInvalidPortName() throws SchematicException {
+    Value v = BooleanValue.getInstance(true);
+    Map<String, Map<String, Value>> portAttrMap = ImmutableMap.of(
+        PORT_NAME, new HashMap<>(),
+        "bogusPort", new HashMap<>());
+    new NodeValue(hasABCNodeAttr, ImmutableMap.of("abc", v), portAttrMap);
+  }
+
+  @Test
+  public void testGetAttribute() throws SchematicException {
+    Value v = BooleanValue.getInstance(true);
+    NodeValue n = new NodeValue(
+        hasABCNodeAttr,
+        ImmutableMap.of("abc", v),
+        PORT_ATTRS
+    );
+    assertEquals(v, n.getAttribute("abc"));
+  }
+
+  @Test(expected = org.manifold.compiler.UndeclaredAttributeException.class)
+  public void testGetAttribute_nonexistent() throws SchematicException {
+    NodeValue n = new NodeValue(hasNoAttrs, new HashMap<>(), PORT_ATTRS);
+    n.getAttribute("bogus");
+  }
+
+  @Test
+  public void testGetPort() throws SchematicException {
+    NodeValue n = new NodeValue(hasNoAttrs, new HashMap<>(), PORT_ATTRS);
+    PortValue port = n.getPort(PORT_NAME);
+    assertEquals(defaultPortDefinition, port.getType());
+  }
+
+  @Test(expected = UndeclaredIdentifierException.class)
+  public void testGetPort_nonexistent() throws SchematicException {
+    NodeValue n = new NodeValue(hasNoAttrs, new HashMap<>(), PORT_ATTRS);
+    n.getPort("bogus");
+  }
+
+  @Test
+  public void testPortsWithValidAttributes() throws SchematicException {
+    PortTypeValue portTypeWithAttr =
+        new PortTypeValue(ImmutableMap.of(PORT_ATTR_KEY, boolType));
+    Map<String, PortTypeValue> portTypeMap =
+        ImmutableMap.of(PORT_NAME, portTypeWithAttr);
+    NodeTypeValue withPortAttrs = new NodeTypeValue(
+        ImmutableMap.of(),
+        portTypeMap
+    );
+    BooleanValue v = BooleanValue.getInstance(false);
+    Map<String, Map<String, Value>> portAttrMap = ImmutableMap.of(PORT_NAME,
+        ImmutableMap.of(PORT_ATTR_KEY, v));
+    NodeValue n = new NodeValue(withPortAttrs, ImmutableMap.of(), portAttrMap);
+    assertEquals(v, n.getPort(PORT_NAME).getAttribute(PORT_ATTR_KEY));
+  }
+}
diff --git a/src/test/java/org/manifold/intermediate/TestPort.java b/src/test/java/org/manifold/compiler/TestPort.java
similarity index 58%
rename from src/test/java/org/manifold/intermediate/TestPort.java
rename to src/test/java/org/manifold/compiler/TestPort.java
index b9b6189..90dec4c 100644
--- a/src/test/java/org/manifold/intermediate/TestPort.java
+++ b/src/test/java/org/manifold/compiler/TestPort.java
@@ -1,4 +1,4 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
 
 import static org.junit.Assert.assertEquals;
 
@@ -9,26 +9,27 @@
 
 import java.util.HashMap;
 import java.util.Map;
+import org.manifold.compiler.middle.SchematicException;
 
 public class TestPort {
 
-  private static final Type boolType = BooleanType.getInstance();
-  private static final PortType defaultPortType =
-      new PortType(ImmutableMap.of("v", boolType));
+  private static final TypeValue boolType = BooleanTypeValue.getInstance();
+  private static final PortTypeValue defaultPortType =
+      new PortTypeValue(ImmutableMap.of("v", boolType));
   private static final String PORT_NAME = "testport";
-  private static final Value v = new BooleanValue(boolType, true);
+  private static final Value v = BooleanValue.getInstance(true);
   
-  private Node parent;
-  private Port port;
+  private NodeValue parent;
+  private PortValue port;
   
   @Before
   public void setup() throws SchematicException {
-    Map<String, PortType> portTypeMap =
+    Map<String, PortTypeValue> portTypeMap =
         ImmutableMap.of(PORT_NAME, defaultPortType);
     Map<String, Map<String, Value>> portMap =
         ImmutableMap.of(PORT_NAME, ImmutableMap.of("v", v));
-    NodeType parentType = new NodeType(new HashMap<>(), portTypeMap);
-    parent = new Node(parentType, new HashMap<>(), portMap);
+    NodeTypeValue parentType = new NodeTypeValue(new HashMap<>(), portTypeMap);
+    parent = new NodeValue(parentType, new HashMap<>(), portMap);
     port = parent.getPort(PORT_NAME);
   }
 
@@ -37,7 +38,7 @@ public void testGetAttribute() throws UndeclaredAttributeException {
     assertEquals(v, port.getAttribute("v"));
   }
 
-  @Test(expected = org.manifold.intermediate.UndeclaredAttributeException.class)
+  @Test(expected = org.manifold.compiler.UndeclaredAttributeException.class)
   public void testGetAttribute_nonexistent()
       throws UndeclaredAttributeException {
     port.getAttribute("bogus");
diff --git a/src/test/java/org/manifold/intermediate/TestSerialization.java b/src/test/java/org/manifold/compiler/TestSerialization.java
similarity index 72%
rename from src/test/java/org/manifold/intermediate/TestSerialization.java
rename to src/test/java/org/manifold/compiler/TestSerialization.java
index 2722464..b029b70 100644
--- a/src/test/java/org/manifold/intermediate/TestSerialization.java
+++ b/src/test/java/org/manifold/compiler/TestSerialization.java
@@ -1,4 +1,4 @@
-package org.manifold.intermediate;
+package org.manifold.compiler;
 
 import static org.junit.Assert.assertTrue;
 
@@ -10,6 +10,8 @@
 import java.io.IOException;
 import java.io.StringWriter;
 import java.util.HashMap;
+import org.manifold.compiler.middle.Schematic;
+import org.manifold.compiler.middle.SchematicException;
 
 public class TestSerialization {
 
@@ -39,31 +41,43 @@ public void setup() throws SchematicException {
     testSchematic = new Schematic(TEST_SCHEMATIC_NAME);
 
     // port type
-    PortType din = new PortType(new HashMap<>());
-    PortType dout = new PortType(new HashMap<>());
+    PortTypeValue din = new PortTypeValue(new HashMap<>());
+    PortTypeValue dout = new PortTypeValue(new HashMap<>());
     testSchematic.addPortType(DIGITAL_IN, din);
     testSchematic.addPortType(DIGITAL_OUT, dout);
 
     // node type
-    HashMap<String, PortType> dinPortMap = new HashMap<>();
+    HashMap<String, PortTypeValue> dinPortMap = new HashMap<>();
     dinPortMap.put(IN_PORT_NAME, din);
 
-    HashMap<String, PortType> doutPortMap = new HashMap<>();
+    HashMap<String, PortTypeValue> doutPortMap = new HashMap<>();
     doutPortMap.put(OUT_PORT_NAME, dout);
 
-    NodeType dinNodeType = new NodeType(new HashMap<>(), dinPortMap);
-    NodeType doutNodeType = new NodeType(new HashMap<>(), doutPortMap);
+    NodeTypeValue dinNodeType = new NodeTypeValue(new HashMap<>(), dinPortMap);
+    NodeTypeValue doutNodeType = new NodeTypeValue(
+        new HashMap<>(),
+        doutPortMap
+    );
 
     testSchematic.addNodeType(IN_NODE_NAME, dinNodeType);
     testSchematic.addNodeType(OUT_NODE_NAME, doutNodeType);
 
     // node
-    Node inNode = new Node(dinNodeType, new HashMap<>(), new HashMap<>());
-    Node outNode = new Node(doutNodeType, new HashMap<>(), new HashMap<>());
+    NodeValue inNode = new NodeValue(
+        dinNodeType,
+        new HashMap<>(),
+        new HashMap<>()
+    );
+    
+    NodeValue outNode = new NodeValue(
+        doutNodeType,
+        new HashMap<>(),
+        new HashMap<>()
+    );
 
     // connection
     ConnectionType conType = new ConnectionType(new HashMap<>());
-    Connection con = new Connection(
+    ConnectionValue con = new ConnectionValue(
         conType,
         inNode.getPort(IN_PORT_NAME),
         outNode.getPort(OUT_PORT_NAME),
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestTypeMismatchException.java b/src/test/java/org/manifold/compiler/TestTypeMismatchException.java
similarity index 78%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestTypeMismatchException.java
rename to src/test/java/org/manifold/compiler/TestTypeMismatchException.java
index feff558..48b797b 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestTypeMismatchException.java
+++ b/src/test/java/org/manifold/compiler/TestTypeMismatchException.java
@@ -1,17 +1,18 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler;
 
 import static org.junit.Assert.*;
 
 import org.junit.Test;
+import org.manifold.compiler.front.TypeMismatchException;
 
 public class TestTypeMismatchException {
 
   public TypeValue getTypeValueInstance(){
-    return BitTypeValue.getInstance();
+    return BooleanTypeValue.getInstance();
   }
   
   public Value getValueInstance(){
-    return BitValue.getInstance(false);
+    return BooleanValue.getInstance(false);
   }
   
   public TypeMismatchException getInstance(){
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestTypeTypeValue.java b/src/test/java/org/manifold/compiler/TestTypeTypeValue.java
similarity index 71%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestTypeTypeValue.java
rename to src/test/java/org/manifold/compiler/TestTypeTypeValue.java
index 362ba5d..9d0883e 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestTypeTypeValue.java
+++ b/src/test/java/org/manifold/compiler/TestTypeTypeValue.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler;
 
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.junit.Assert.*;
@@ -23,22 +23,12 @@ public void testGetType() {
   
   @Test
   public void isSubtypeOf_false() {
-    assertFalse(getInstance().isSubtypeOf(BitTypeValue.getInstance()));
+    assertFalse(getInstance().isSubtypeOf(BooleanTypeValue.getInstance()));
   }
   
   @Test
   public void isSubtypeOf_true() {
     assertTrue(getInstance().isSubtypeOf(getInstance()));
   }
-  
-  @Test
-  public void verify() {
-    getInstance().verify();
-  }
-  
-  @Test
-  public void testVerify() {
-    getInstance().verify();
-  }
 
 }
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestTypeValue.java b/src/test/java/org/manifold/compiler/TestTypeValue.java
similarity index 87%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestTypeValue.java
rename to src/test/java/org/manifold/compiler/TestTypeValue.java
index 416a6b9..e32bcb3 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestTypeValue.java
+++ b/src/test/java/org/manifold/compiler/TestTypeValue.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler;
 
 import static org.junit.Assert.*;
 
@@ -24,7 +24,7 @@ public void verify() {}
 
   private TypeValue getInstance() {
     // TypeValue is abstract so we use a simple implementation.
-    return BitTypeValue.getInstance();
+    return BooleanTypeValue.getInstance();
   }
 
   @Test
@@ -44,13 +44,13 @@ public void isSubtypeOf_equal() {
 
   @Test
   public void isSubtypeOf_subtype() {
-    assertTrue(BitTypeValue.getInstance().isSubtypeOf(
+    assertTrue(BooleanTypeValue.getInstance().isSubtypeOf(
         TypeTypeValue.getInstance()));
   }
 
   @Test
   public void isSubtypeOf_false() {
-    assertFalse(BitTypeValue.getInstance().isSubtypeOf(
+    assertFalse(BooleanTypeValue.getInstance().isSubtypeOf(
         FacadeTypeValue.getInstance()));
   }
 
diff --git a/src/test/java/org/manifold/compiler/TestValue.java b/src/test/java/org/manifold/compiler/TestValue.java
new file mode 100644
index 0000000..928a04c
--- /dev/null
+++ b/src/test/java/org/manifold/compiler/TestValue.java
@@ -0,0 +1,21 @@
+package org.manifold.compiler;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import java.util.HashMap;
+import org.manifold.compiler.middle.SchematicException;
+
+public class TestValue {
+
+  @Test
+  public void testRetrieveType() throws SchematicException {
+    NodeTypeValue nDef = new NodeTypeValue(new HashMap<>(), new HashMap<>());
+    Value dom = new NodeValue(nDef, new HashMap<>(), new HashMap<>());
+    TypeValue expected = nDef;
+    TypeValue actual = dom.getType();
+    assertEquals(expected, actual);
+  }
+
+}
diff --git a/src/test/java/org/manifold/intermediate/TestSchematic.java b/src/test/java/org/manifold/compiler/back/TestSchematic.java
similarity index 73%
rename from src/test/java/org/manifold/intermediate/TestSchematic.java
rename to src/test/java/org/manifold/compiler/back/TestSchematic.java
index ad0c2b9..06b32de 100644
--- a/src/test/java/org/manifold/intermediate/TestSchematic.java
+++ b/src/test/java/org/manifold/compiler/back/TestSchematic.java
@@ -1,5 +1,22 @@
-package org.manifold.intermediate;
+package org.manifold.compiler.back;
 
+import org.manifold.compiler.middle.SchematicException;
+import org.manifold.compiler.middle.Schematic;
+import org.manifold.compiler.StringTypeValue;
+import org.manifold.compiler.ConnectionType;
+import org.manifold.compiler.ConstraintType;
+import org.manifold.compiler.UndeclaredIdentifierException;
+import org.manifold.compiler.PortTypeValue;
+import org.manifold.compiler.ConstraintValue;
+import org.manifold.compiler.TypeValue;
+import org.manifold.compiler.MultipleAssignmentException;
+import org.manifold.compiler.NodeValue;
+import org.manifold.compiler.PortValue;
+import org.manifold.compiler.ConnectionValue;
+import org.manifold.compiler.IntegerTypeValue;
+import org.manifold.compiler.MultipleDefinitionException;
+import org.manifold.compiler.NodeTypeValue;
+import org.manifold.compiler.Value;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.fail;
@@ -14,24 +31,24 @@
 
 public class TestSchematic {
   
-  private static final PortType defaultPortDefinition =
-      new PortType(new HashMap<>());
+  private static final PortTypeValue defaultPortDefinition =
+      new PortTypeValue(new HashMap<>());
   private static final String PORT_NAME1 = "P1";
   private static final String PORT_NAME2 = "P2";
   
-  private Node n;
-  private Port p1, p2;
+  private NodeValue n;
+  private PortValue p1, p2;
   
   @Before
   public void setup() throws SchematicException {
-    Map<String, PortType> portMap = ImmutableMap.of(
+    Map<String, PortTypeValue> portMap = ImmutableMap.of(
         PORT_NAME1, defaultPortDefinition,
         PORT_NAME2, defaultPortDefinition);
     Map<String, Map<String, Value>> portAttrMap = ImmutableMap.of(
         PORT_NAME1, ImmutableMap.of(),
         PORT_NAME2, ImmutableMap.of());
-    NodeType nType = new NodeType(new HashMap<>(), portMap);
-    n = new Node(nType, new HashMap<>(), portAttrMap);
+    NodeTypeValue nType = new NodeTypeValue(new HashMap<>(), portMap);
+    n = new NodeValue(nType, new HashMap<>(), portAttrMap);
     
     p1 = n.getPort(PORT_NAME1);
     p2 = n.getPort(PORT_NAME2);
@@ -40,7 +57,7 @@ public void setup() throws SchematicException {
   @Test
   public void testAddTypeDef() throws MultipleDefinitionException {
     Schematic s = new Schematic("test");
-    Type t1 = IntegerType.getInstance();
+    TypeValue t1 = IntegerTypeValue.getInstance();
     s.addUserDefinedType("foo", t1);
   }
   
@@ -52,12 +69,12 @@ public void testAddTypeDef_multipleDefinitions()
     // is the same string.
     Schematic s = new Schematic("test");
     try {
-      Type t1 = IntegerType.getInstance();
+      TypeValue t1 = IntegerTypeValue.getInstance();
       s.addUserDefinedType("foo", t1);
     } catch (MultipleDefinitionException mde) {
       fail("exception thrown too early: " + mde.getMessage());
     }
-    Type t2 = IntegerType.getInstance();
+    TypeValue t2 = IntegerTypeValue.getInstance();
     s.addUserDefinedType("foo", t2);
   }
   
@@ -68,7 +85,7 @@ public void testAddTypeDef_maskDefaultType()
     // of "Int". Since "Int" is a built-in type, this should result in a
     // MultipleDefinitionException being thrown.
     Schematic s = new Schematic("test");
-    Type td = StringType.getInstance();
+    TypeValue td = StringTypeValue.getInstance();
     s.addUserDefinedType("Int", td);
   }
   
@@ -76,9 +93,9 @@ public void testAddTypeDef_maskDefaultType()
   public void testGetTypeDef()
       throws UndeclaredIdentifierException, MultipleDefinitionException {
     Schematic s = new Schematic("test");
-    Type expected = IntegerType.getInstance();
+    TypeValue expected = IntegerTypeValue.getInstance();
     s.addUserDefinedType("foo", expected);
-    Type actual = s.getUserDefinedType("foo");
+    TypeValue actual = s.getUserDefinedType("foo");
     assertEquals(expected, actual);
   }
   
@@ -86,13 +103,13 @@ public void testGetTypeDef()
   public void testGetTypeDef_notDeclared()
       throws UndeclaredIdentifierException {
     Schematic s = new Schematic("test");
-    Type bogus = s.getUserDefinedType("does-not-exist");
+    TypeValue bogus = s.getUserDefinedType("does-not-exist");
   }
   
   @Test
   public void testAddPortDef() throws MultipleDefinitionException {
     Schematic s = new Schematic("test");
-    PortType e1 = new PortType(new HashMap<>());
+    PortTypeValue e1 = new PortTypeValue(new HashMap<>());
     s.addPortType("n1", e1);
   }
   
@@ -103,12 +120,12 @@ public void testAddPortDef_multipleDefinitions()
     // is the same string.
     Schematic s = new Schematic("test");
     try {
-      PortType n1 = new PortType(new HashMap<>());
+      PortTypeValue n1 = new PortTypeValue(new HashMap<>());
       s.addPortType("foo", n1);
     } catch (MultipleDefinitionException mde) {
       fail("exception thrown too early: " + mde.getMessage());
     }
-    PortType n2 = new PortType(new HashMap<>());
+    PortTypeValue n2 = new PortTypeValue(new HashMap<>());
     s.addPortType("foo", n2);
   }
   
@@ -116,9 +133,9 @@ public void testAddPortDef_multipleDefinitions()
   public void testGetPortDef()
       throws UndeclaredIdentifierException, MultipleDefinitionException{
     Schematic s = new Schematic("test");
-    PortType expected = new PortType(new HashMap<>());
+    PortTypeValue expected = new PortTypeValue(new HashMap<>());
     s.addPortType("foo", expected);
-    PortType actual = s.getPortType("foo");
+    PortTypeValue actual = s.getPortType("foo");
     assertEquals(expected, actual);
   }
   
@@ -126,13 +143,13 @@ public void testGetPortDef()
   public void testGetPortDef_notDeclared()
       throws UndeclaredIdentifierException {
     Schematic s = new Schematic("test");
-    PortType bogus = s.getPortType("does-not-exist");
+    PortTypeValue bogus = s.getPortType("does-not-exist");
   }
   
   @Test
   public void testAddNodeDef() throws MultipleDefinitionException {
     Schematic s = new Schematic("test");
-    NodeType n1 = new NodeType(new HashMap<>(), new HashMap<>());
+    NodeTypeValue n1 = new NodeTypeValue(new HashMap<>(), new HashMap<>());
     s.addNodeType("n1", n1);
   }
   
@@ -143,12 +160,12 @@ public void testAddNodeDef_multipleDefinitions()
     // is the same string.
     Schematic s = new Schematic("test");
     try {
-      NodeType n1 = new NodeType(new HashMap<>(), new HashMap<>());
+      NodeTypeValue n1 = new NodeTypeValue(new HashMap<>(), new HashMap<>());
       s.addNodeType("foo", n1);
     } catch (MultipleDefinitionException mde) {
       fail("exception thrown too early: " + mde.getMessage());
     }
-    NodeType n2 = new NodeType(new HashMap<>(), new HashMap<>());
+    NodeTypeValue n2 = new NodeTypeValue(new HashMap<>(), new HashMap<>());
     s.addNodeType("foo", n2);
   }
   
@@ -156,9 +173,12 @@ public void testAddNodeDef_multipleDefinitions()
   public void testGetNodeDef()
       throws UndeclaredIdentifierException, MultipleDefinitionException{
     Schematic s = new Schematic("test");
-    NodeType expected = new NodeType(new HashMap<>(), new HashMap<>());
+    NodeTypeValue expected = new NodeTypeValue(
+        new HashMap<>(),
+        new HashMap<>()
+    );
     s.addNodeType("foo", expected);
-    NodeType actual = s.getNodeType("foo");
+    NodeTypeValue actual = s.getNodeType("foo");
     assertEquals(expected, actual);
   }
   
@@ -166,7 +186,7 @@ public void testGetNodeDef()
   public void testGetNodeDef_notDeclared()
       throws UndeclaredIdentifierException {
     Schematic s = new Schematic("test");
-    NodeType bogus = s.getNodeType("does-not-exist");
+    NodeTypeValue bogus = s.getNodeType("does-not-exist");
   }
   
   @Test
@@ -258,11 +278,11 @@ public void testSeparationOfNamespaces_Definitions()
     // definition" exception.
     Schematic s = new Schematic("test");
     
-    Type t1 = StringType.getInstance();
+    TypeValue t1 = StringTypeValue.getInstance();
     ConstraintType ct1 = new ConstraintType(new HashMap<>());
     ConnectionType cn1 = new ConnectionType(new HashMap<>());
-    NodeType n1 = new NodeType(new HashMap<>(), new HashMap<>());
-    PortType e1 = new PortType(new HashMap<>());
+    NodeTypeValue n1 = new NodeTypeValue(new HashMap<>(), new HashMap<>());
+    PortTypeValue e1 = new PortTypeValue(new HashMap<>());
     
     s.addUserDefinedType("foo", t1);
     s.addConstraintType("foo", ct1);
@@ -274,33 +294,33 @@ public void testSeparationOfNamespaces_Definitions()
   @Test
   public void testAddNode() throws SchematicException {
     Schematic s = new Schematic("test");
-    NodeType n1Type = new NodeType(new HashMap<>(), new HashMap<>());
-    Node n1 = new Node(n1Type, new HashMap<>(), new HashMap<>());
+    NodeTypeValue n1Type = new NodeTypeValue(new HashMap<>(), new HashMap<>());
+    NodeValue n1 = new NodeValue(n1Type, new HashMap<>(), new HashMap<>());
     s.addNode("n1", n1);
   }
   
-  @Test(expected = org.manifold.intermediate.MultipleAssignmentException.class)
+  @Test(expected = org.manifold.compiler.MultipleAssignmentException.class)
   public void testAddNode_multipleInstantiation() throws SchematicException {
     Schematic s = new Schematic("test");
-    NodeType n1Type = new NodeType(new HashMap<>(), new HashMap<>());
+    NodeTypeValue n1Type = new NodeTypeValue(new HashMap<>(), new HashMap<>());
     try {
-      Node n1 = new Node(n1Type, new HashMap<>(), new HashMap<>());
+      NodeValue n1 = new NodeValue(n1Type, new HashMap<>(), new HashMap<>());
       s.addNode("n1", n1);
     } catch (MultipleAssignmentException mie) {
       fail("exception thrown too early");
     }
-    Node n1Dup = new Node(n1Type, new HashMap<>(), new HashMap<>());
+    NodeValue n1Dup = new NodeValue(n1Type, new HashMap<>(), new HashMap<>());
     s.addNode("n1", n1Dup);
   }
   
   @Test
   public void testGetNode() throws SchematicException {
     Schematic s = new Schematic("test");
-    NodeType n1Type = new NodeType(new HashMap<>(), new HashMap<>());
-    Node n1 = new Node(n1Type, new HashMap<>(), new HashMap<>());
+    NodeTypeValue n1Type = new NodeTypeValue(new HashMap<>(), new HashMap<>());
+    NodeValue n1 = new NodeValue(n1Type, new HashMap<>(), new HashMap<>());
     s.addNode("n1", n1);
     
-    Node actual = s.getNode("n1");
+    NodeValue actual = s.getNode("n1");
     assertSame(n1, actual);
   }
   
@@ -315,22 +335,27 @@ public void testGetNode_notInstantiated()
   public void testAddConnection() throws SchematicException {
     Schematic s = new Schematic("test");
     ConnectionType c1Type = new ConnectionType(new HashMap<>());
-    Connection c1 = new Connection(c1Type, p1, p2, new HashMap<>());
+    ConnectionValue c1 = new ConnectionValue(c1Type, p1, p2, new HashMap<>());
     s.addConnection("c1", c1);
   }
   
-  @Test(expected = org.manifold.intermediate.MultipleAssignmentException.class)
+  @Test(expected = org.manifold.compiler.MultipleAssignmentException.class)
   public void testAddConnection_multipleInstantiation()
       throws SchematicException {
     Schematic s = new Schematic("test");
     ConnectionType c1Type = new ConnectionType(new HashMap<>());
     try {
-      Connection c1 = new Connection(c1Type, p1, p2, new HashMap<>());
+      ConnectionValue c1 = new ConnectionValue(c1Type, p1, p2, new HashMap<>());
       s.addConnection("c1", c1);
     } catch (MultipleAssignmentException mie) {
       fail("exception thrown too early");
     }
-    Connection c1Dup = new Connection(c1Type, p1, p2, new HashMap<>());
+    ConnectionValue c1Dup = new ConnectionValue(
+        c1Type,
+        p1,
+        p2,
+        new HashMap<>()
+    );
     s.addConnection("c1", c1Dup);
   }
   
@@ -338,9 +363,9 @@ public void testAddConnection_multipleInstantiation()
   public void testGetConnection() throws SchematicException {
     Schematic s = new Schematic("test");
     ConnectionType c1Type = new ConnectionType(new HashMap<>());
-    Connection c1 = new Connection(c1Type, p1, p2, new HashMap<>());
+    ConnectionValue c1 = new ConnectionValue(c1Type, p1, p2, new HashMap<>());
     s.addConnection("c1", c1);
-    Connection actual = s.getConnection("c1");
+    ConnectionValue actual = s.getConnection("c1");
     assertSame(c1, actual);
   }
   
@@ -355,7 +380,7 @@ public void testGetConnection_notInstantiated()
   public void testAddConstraint() throws SchematicException {
     Schematic s = new Schematic("test");
     ConstraintType c1Type = new ConstraintType(new HashMap<>());
-    Constraint c1 = new Constraint(c1Type, new HashMap<>());
+    ConstraintValue c1 = new ConstraintValue(c1Type, new HashMap<>());
     s.addConstraint("c1", c1);
   }
   
@@ -366,13 +391,13 @@ public void testAddConstraint_multipleInstantiation()
     ConstraintType c1Type = new ConstraintType(new HashMap<>());
     
     try {
-      Constraint c1 = new Constraint(c1Type, new HashMap<>());
+      ConstraintValue c1 = new ConstraintValue(c1Type, new HashMap<>());
       s.addConstraint("c1", c1);
     } catch (MultipleAssignmentException mie) {
       fail("exception thrown too early");
     }
     
-    Constraint c1Dup = new Constraint(c1Type, new HashMap<>());
+    ConstraintValue c1Dup = new ConstraintValue(c1Type, new HashMap<>());
     s.addConstraint("c1", c1Dup);
   }
   
@@ -380,10 +405,10 @@ public void testAddConstraint_multipleInstantiation()
   public void testGetConstraint() throws SchematicException {
     Schematic s = new Schematic("test");
     ConstraintType c1Type = new ConstraintType(new HashMap<>());
-    Constraint c1 = new Constraint(c1Type, new HashMap<>());
+    ConstraintValue c1 = new ConstraintValue(c1Type, new HashMap<>());
     s.addConstraint("c1", c1);
     
-    Constraint actual = s.getConstraint("c1");
+    ConstraintValue actual = s.getConstraint("c1");
     assertSame(c1, actual);
   }
   
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestMultipleAssignmentException.java b/src/test/java/org/manifold/compiler/front/TestMultipleAssignmentException.java
similarity index 87%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestMultipleAssignmentException.java
rename to src/test/java/org/manifold/compiler/front/TestMultipleAssignmentException.java
index 2fdcf32..b71145d 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestMultipleAssignmentException.java
+++ b/src/test/java/org/manifold/compiler/front/TestMultipleAssignmentException.java
@@ -1,5 +1,6 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
+import org.manifold.compiler.BooleanTypeValue;
 import static org.junit.Assert.*;
 
 import org.junit.Test;
@@ -19,7 +20,7 @@ private VariableIdentifier getVariableIdentifierInstance() {
   }
 
   private Expression getTypeExpression() {
-    return new LiteralExpression(BitTypeValue.getInstance());
+    return new LiteralExpression(BooleanTypeValue.getInstance());
   }
   
   public Variable getVariableInstance() {
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestMultipleDefinitionException.java b/src/test/java/org/manifold/compiler/front/TestMultipleDefinitionException.java
similarity index 95%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestMultipleDefinitionException.java
rename to src/test/java/org/manifold/compiler/front/TestMultipleDefinitionException.java
index 5f1c724..d716017 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestMultipleDefinitionException.java
+++ b/src/test/java/org/manifold/compiler/front/TestMultipleDefinitionException.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
 import static org.junit.Assert.*;
 
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestNamespace.java b/src/test/java/org/manifold/compiler/front/TestNamespace.java
similarity index 85%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestNamespace.java
rename to src/test/java/org/manifold/compiler/front/TestNamespace.java
index eaa7b01..4b0ee17 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestNamespace.java
+++ b/src/test/java/org/manifold/compiler/front/TestNamespace.java
@@ -1,5 +1,6 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
+import org.manifold.compiler.BooleanTypeValue;
 import static org.junit.Assert.*;
 
 import org.junit.Test;
@@ -20,7 +21,7 @@ private VariableIdentifier getVariableIdentifier() {
   }
 
   private Expression getTypeExpression() {
-    return new LiteralExpression(BitTypeValue.getInstance());
+    return new LiteralExpression(BooleanTypeValue.getInstance());
   }
 
   @Test
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestNamespaceIdentifier.java b/src/test/java/org/manifold/compiler/front/TestNamespaceIdentifier.java
similarity index 97%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestNamespaceIdentifier.java
rename to src/test/java/org/manifold/compiler/front/TestNamespaceIdentifier.java
index a978b17..69141ca 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestNamespaceIdentifier.java
+++ b/src/test/java/org/manifold/compiler/front/TestNamespaceIdentifier.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
 import static org.junit.Assert.*;
 
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestScope.java b/src/test/java/org/manifold/compiler/front/TestScope.java
similarity index 94%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestScope.java
rename to src/test/java/org/manifold/compiler/front/TestScope.java
index 59613d4..3317afd 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestScope.java
+++ b/src/test/java/org/manifold/compiler/front/TestScope.java
@@ -1,5 +1,7 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
+import org.manifold.compiler.BooleanValue;
+import org.manifold.compiler.BooleanTypeValue;
 import static org.junit.Assert.*;
 
 import org.junit.Test;
@@ -32,12 +34,12 @@ private VariableIdentifier getVariableIdentifier() {
   }
 
   private Expression getTypeExpression() {
-    return new LiteralExpression(BitTypeValue.getInstance());
+    return new LiteralExpression(BooleanTypeValue.getInstance());
   }
 
   // TODO(lucas) return an instance of the type
   private Expression getValueExpression() {
-    return new LiteralExpression(BitValue.getInstance(true));
+    return new LiteralExpression(BooleanValue.getInstance(true));
   }
 
   @Test
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestVariable.java b/src/test/java/org/manifold/compiler/front/TestVariable.java
similarity index 82%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestVariable.java
rename to src/test/java/org/manifold/compiler/front/TestVariable.java
index 2714165..18f0f61 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestVariable.java
+++ b/src/test/java/org/manifold/compiler/front/TestVariable.java
@@ -1,5 +1,7 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
+import org.manifold.compiler.BooleanValue;
+import org.manifold.compiler.BooleanTypeValue;
 import static org.junit.Assert.*;
 
 import org.junit.Test;
@@ -19,11 +21,11 @@ private Variable getVariable() {
   }
 
   private Expression getTypeExpression(){
-    return new LiteralExpression(BitTypeValue.getInstance());
+    return new LiteralExpression(BooleanTypeValue.getInstance());
   }
 
   private Expression getValueExpression(){
-    return new LiteralExpression(BitValue.getInstance(true));
+    return new LiteralExpression(BooleanValue.getInstance(true));
   }
 
   @Test
@@ -66,7 +68,7 @@ public void verify_nontypeThrow() throws
 
     Variable v = new Variable(
         getVariableIdentifier(),
-        new LiteralExpression(BitValue.getInstance(false))
+        new LiteralExpression(BooleanValue.getInstance(false))
     );
     v.verify();
   }
@@ -78,9 +80,9 @@ public void verify_typeMismatchThrow() throws
 
     Variable v = new Variable(
         getVariableIdentifier(),
-        new LiteralExpression(BitTypeValue.getInstance())
+        new LiteralExpression(BooleanTypeValue.getInstance())
     );
-    v.setValue(new LiteralExpression(BitTypeValue.getInstance()));
+    v.setValue(new LiteralExpression(BooleanTypeValue.getInstance()));
     v.verify();
   }
 }
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestVariableIdentifier.java b/src/test/java/org/manifold/compiler/front/TestVariableIdentifier.java
similarity index 98%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestVariableIdentifier.java
rename to src/test/java/org/manifold/compiler/front/TestVariableIdentifier.java
index 3f713a5..90e6751 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestVariableIdentifier.java
+++ b/src/test/java/org/manifold/compiler/front/TestVariableIdentifier.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
 import static org.junit.Assert.*;
 
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestVariableNotAssignedException.java b/src/test/java/org/manifold/compiler/front/TestVariableNotAssignedException.java
similarity index 87%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestVariableNotAssignedException.java
rename to src/test/java/org/manifold/compiler/front/TestVariableNotAssignedException.java
index 35ca4fd..e23dd0e 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestVariableNotAssignedException.java
+++ b/src/test/java/org/manifold/compiler/front/TestVariableNotAssignedException.java
@@ -1,5 +1,6 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
+import org.manifold.compiler.BooleanTypeValue;
 import static org.junit.Assert.*;
 
 import org.junit.Test;
@@ -18,7 +19,7 @@ private VariableIdentifier getVariableIdentifierInstance() {
   }
 
   private Expression getTypeExpression(){
-    return new LiteralExpression(BitTypeValue.getInstance());
+    return new LiteralExpression(BooleanTypeValue.getInstance());
   }
   
   public Variable getVariableInstance(){
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestVariableNotDefinedException.java b/src/test/java/org/manifold/compiler/front/TestVariableNotDefinedException.java
similarity index 95%
rename from src/test/java/org/manifold/frontend/syntaxtree/TestVariableNotDefinedException.java
rename to src/test/java/org/manifold/compiler/front/TestVariableNotDefinedException.java
index 4f64632..239f0ad 100644
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestVariableNotDefinedException.java
+++ b/src/test/java/org/manifold/compiler/front/TestVariableNotDefinedException.java
@@ -1,4 +1,4 @@
-package org.manifold.frontend.syntaxtree;
+package org.manifold.compiler.front;
 
 import static org.junit.Assert.*;
 
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestBitTypeValue.java b/src/test/java/org/manifold/frontend/syntaxtree/TestBitTypeValue.java
deleted file mode 100644
index be194c5..0000000
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestBitTypeValue.java
+++ /dev/null
@@ -1,28 +0,0 @@
-package org.manifold.frontend.syntaxtree;
-
-import static org.hamcrest.CoreMatchers.instanceOf;
-import static org.junit.Assert.*;
-
-import org.junit.Test;
-
-public class TestBitTypeValue {
-
-  private BitTypeValue getInstance() {
-    return BitTypeValue.getInstance();
-  }
-  
-  @Test
-  public void testStaticGetInstance() {
-    assertThat(
-      BitTypeValue.getInstance(),
-      instanceOf(BitTypeValue.class)
-    );
-  }
-  
-  @Test
-  public void testVerify() {
-    getInstance().verify();
-  }
-
-
-}
diff --git a/src/test/java/org/manifold/frontend/syntaxtree/TestValue.java b/src/test/java/org/manifold/frontend/syntaxtree/TestValue.java
deleted file mode 100644
index 716e91f..0000000
--- a/src/test/java/org/manifold/frontend/syntaxtree/TestValue.java
+++ /dev/null
@@ -1,3 +0,0 @@
-package org.manifold.frontend.syntaxtree;
-
-public class TestValue { }
diff --git a/src/test/java/org/manifold/intermediate/TestConstraint.java b/src/test/java/org/manifold/intermediate/TestConstraint.java
deleted file mode 100644
index 07757b7..0000000
--- a/src/test/java/org/manifold/intermediate/TestConstraint.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package org.manifold.intermediate;
-
-import static org.junit.Assert.assertEquals;
-
-import com.google.common.collect.ImmutableMap;
-
-import org.junit.Test;
-
-public class TestConstraint {
-
-  private static final Type boolType = BooleanType.getInstance();
-  private static final ConstraintType defaultConstraintDefinition =
-      new ConstraintType(ImmutableMap.of("v", boolType));
-
-  @Test
-  public void testGetAttribute() throws SchematicException {
-    Value v = new BooleanValue(boolType, true);
-    Constraint ept = new Constraint(defaultConstraintDefinition,
-        ImmutableMap.of("v", v));
-    Value vActual = ept.getAttribute("v");
-    assertEquals(v, vActual);
-  }
-
-  @Test(expected = org.manifold.intermediate.UndeclaredAttributeException.class)
-  public void testGetAttribute_nonexistent() throws SchematicException {
-    Value v = new BooleanValue(boolType, true);
-    Constraint ept = new Constraint(defaultConstraintDefinition,
-        ImmutableMap.of("v", v));
-    ept.getAttribute("bogus");
-  }
-
-  @Test(expected = org.manifold.intermediate.UndeclaredAttributeException.class)
-  public void testMissingAttribute() throws SchematicException {
-    new Constraint(defaultConstraintDefinition, ImmutableMap.of());
-  }
-
-  @Test(expected = org.manifold.intermediate.InvalidAttributeException.class)
-  public void testExtraAttribute() throws Exception {
-    Value v = new BooleanValue(boolType, true);
-    new Constraint(defaultConstraintDefinition,
-        ImmutableMap.of("v", v, "vBogus", v));
-  }
-}
diff --git a/src/test/java/org/manifold/intermediate/TestNode.java b/src/test/java/org/manifold/intermediate/TestNode.java
deleted file mode 100644
index e95e1ef..0000000
--- a/src/test/java/org/manifold/intermediate/TestNode.java
+++ /dev/null
@@ -1,90 +0,0 @@
-package org.manifold.intermediate;
-
-import static org.junit.Assert.assertEquals;
-
-import com.google.common.collect.ImmutableMap;
-
-import org.junit.Before;
-import org.junit.Test;
-
-import java.util.HashMap;
-import java.util.Map;
-
-public class TestNode {
-
-  private static final PortType defaultPortDefinition =
-      new PortType(new HashMap<>());
-  private static final Type boolType = BooleanType.getInstance();
-  private static final String PORT_NAME = "testport";
-  private static final String PORT_ATTR_KEY = "the truth will set you free";
-  private static final Map<String, Map<String, Value>> PORT_ATTRS =
-      ImmutableMap.of(PORT_NAME, ImmutableMap.of());
-  
-  private NodeType hasNoAttrs;
-  private NodeType hasABCNodeAttr;
-  
-  @Before
-  public void setup() {
-    Map<String, PortType> portMap =
-        ImmutableMap.of(PORT_NAME, defaultPortDefinition);
-    hasNoAttrs = new NodeType(new HashMap<>(), portMap);
-    hasABCNodeAttr = new NodeType(ImmutableMap.of("abc", boolType), portMap);
-  }
-
-  @Test(
-      expected = org.manifold.intermediate.InvalidIdentifierException.class)
-  public void testCreateWithMissingPort() throws SchematicException {
-    Value v = new BooleanValue(boolType, true);
-    new Node(hasABCNodeAttr, ImmutableMap.of("abc", v), new HashMap<>());
-  }
-  
-  @Test(
-      expected = org.manifold.intermediate.UndeclaredIdentifierException.class)
-  public void testCreateWithInvalidPortName() throws SchematicException {
-    Value v = new BooleanValue(boolType, true);
-    Map<String, Map<String, Value>> portAttrMap = ImmutableMap.of(
-        PORT_NAME, new HashMap<>(),
-        "bogusPort", new HashMap<>());
-    new Node(hasABCNodeAttr, ImmutableMap.of("abc", v), portAttrMap);
-  }
-
-  @Test
-  public void testGetAttribute() throws SchematicException {
-    Value v = new BooleanValue(boolType, true);
-    Node n = new Node(hasABCNodeAttr, ImmutableMap.of("abc", v), PORT_ATTRS);
-    assertEquals(v, n.getAttribute("abc"));
-  }
-
-  @Test(expected = org.manifold.intermediate.UndeclaredAttributeException.class)
-  public void testGetAttribute_nonexistent() throws SchematicException {
-    Node n = new Node(hasNoAttrs, new HashMap<>(), PORT_ATTRS);
-    n.getAttribute("bogus");
-  }
-
-  @Test
-  public void testGetPort() throws SchematicException {
-    Node n = new Node(hasNoAttrs, new HashMap<>(), PORT_ATTRS);
-    Port port = n.getPort(PORT_NAME);
-    assertEquals(defaultPortDefinition, port.getType());
-  }
-
-  @Test(expected = UndeclaredIdentifierException.class)
-  public void testGetPort_nonexistent() throws SchematicException {
-    Node n = new Node(hasNoAttrs, new HashMap<>(), PORT_ATTRS);
-    n.getPort("bogus");
-  }
-
-  @Test
-  public void testPortsWithValidAttributes() throws SchematicException {
-    PortType portTypeWithAttr =
-        new PortType(ImmutableMap.of(PORT_ATTR_KEY, boolType));
-    Map<String, PortType> portTypeMap =
-        ImmutableMap.of(PORT_NAME, portTypeWithAttr);
-    NodeType withPortAttrs = new NodeType(ImmutableMap.of(), portTypeMap);
-    BooleanValue v = new BooleanValue(boolType, false);
-    Map<String, Map<String, Value>> portAttrMap = ImmutableMap.of(PORT_NAME,
-        ImmutableMap.of(PORT_ATTR_KEY, v));
-    Node n = new Node(withPortAttrs, ImmutableMap.of(), portAttrMap);
-    assertEquals(v, n.getPort(PORT_NAME).getAttribute(PORT_ATTR_KEY));
-  }
-}
diff --git a/src/test/java/org/manifold/intermediate/TestValue.java b/src/test/java/org/manifold/intermediate/TestValue.java
deleted file mode 100644
index 6a00f54..0000000
--- a/src/test/java/org/manifold/intermediate/TestValue.java
+++ /dev/null
@@ -1,20 +0,0 @@
-package org.manifold.intermediate;
-
-import static org.junit.Assert.assertEquals;
-
-import org.junit.Test;
-
-import java.util.HashMap;
-
-public class TestValue {
-
-  @Test
-  public void testRetrieveType() throws SchematicException {
-    NodeType nDef = new NodeType(new HashMap<>(), new HashMap<>());
-    Value dom = new Node(nDef, new HashMap<>(), new HashMap<>());
-    Type expected = nDef;
-    Type actual = dom.getType();
-    assertEquals(expected, actual);
-  }
-
-}