diff --git a/index.js b/index.js
index fb07f655..841cca1a 100644
--- a/index.js
+++ b/index.js
@@ -217,16 +217,89 @@
   };
 
   //  Accessible :: TypeClass
-  var Accessible = Z.TypeClass(
+  var Accessible = $.TypeClass(
     'sanctuary/Accessible',
-    [],
     function(x) { return x != null; }
   );
 
+  //  Applicative :: TypeClass
+  var Applicative = $.TypeClass(
+    'sanctuary/Applicative',
+    function(x) {
+      return _type(x) === 'Array' ||
+             Apply._test(x) && (hasMethod('of')(x) ||
+                                hasMethod('of')(x.constructor));
+    }
+  );
+
+  //  Apply :: TypeClass
+  var Apply = $.TypeClass(
+    'sanctuary/Apply',
+    function(x) {
+      switch (_type(x)) {
+        case 'Array':
+        case 'Function':
+          return true;
+        default:
+          return Functor._test(x) && hasMethod('ap')(x);
+      }
+    }
+  );
+
+  //  Chain :: TypeClass
+  var Chain = $.TypeClass(
+    'sanctuary/Chain',
+    function(x) {
+      return _type(x) === 'Array' || hasMethod('chain')(x);
+    }
+  );
+
+  //  Extend :: TypeClass
+  var Extend = $.TypeClass(
+    'sanctuary/Extend',
+    hasMethod('extend')
+  );
+
+  //  Foldable :: TypeClass
+  var Foldable = $.TypeClass(
+    'sanctuary/Foldable',
+    function(x) {
+      switch (_type(x)) {
+        case 'Array':
+        case 'Object':
+          return true;
+        default:
+          return hasMethod('reduce')(x);
+      }
+    }
+  );
+
+  //  Functor :: TypeClass
+  var Functor = $.TypeClass(
+    'sanctuary/Functor',
+    function(x) {
+      switch (_type(x)) {
+        case 'Array':
+        case 'Function':
+        case 'Object':
+          return true;
+        default:
+          return hasMethod('map')(x);
+      }
+    }
+  );
+
+  //  Monad :: TypeClass
+  var Monad = $.TypeClass(
+    'sanctuary/Monad',
+    function(x) {
+      return Applicative._test(x) && Chain._test(x);
+    }
+  );
+
   //  Monoid :: TypeClass
-  var Monoid = Z.TypeClass(
+  var Monoid = $.TypeClass(
     'sanctuary/Monoid',
-    [],
     function(x) {
       switch (_type(x)) {
         case 'Array':
@@ -241,9 +314,8 @@
   );
 
   //  Ord :: TypeClass
-  var Ord = Z.TypeClass(
+  var Ord = $.TypeClass(
     'sanctuary/Ord',
-    [],
     function(x) {
       return $.String._test(x) ||
              $.ValidDate._test(x) ||
@@ -251,6 +323,18 @@
     }
   );
 
+  //  Semigroup :: TypeClass
+  var Semigroup = $.TypeClass(
+    'sanctuary/Semigroup',
+    hasMethod('concat')
+  );
+
+  //  Traversable :: TypeClass
+  var Traversable = $.TypeClass(
+    'sanctuary/Traversable',
+    hasMethod('traverse')
+  );
+
   var a = $.TypeVariable('a');
   var b = $.TypeVariable('b');
   var c = $.TypeVariable('c');
@@ -561,7 +645,7 @@
   //. ```
   var concat = S.concat =
   def('concat',
-      {a: [Z.Semigroup]},
+      {a: [Semigroup]},
       [a, a, a],
       Z.concat);
 
@@ -610,8 +694,8 @@
   //. ```
   var map = S.map =
   def('map',
-      {a: [Z.Functor], b: [Z.Functor]},
-      [$.AnyFunction, a, b],
+      {a: [Functor], b: [Functor]},
+      [$.Function, a, b],
       Z.map);
 
   //# reduce :: Foldable f => (a -> b -> a) -> a -> f b -> a
@@ -635,8 +719,8 @@
   //. ```
   var reduce = S.reduce =
   def('reduce',
-      {b: [Z.Foldable]},
-      [$.AnyFunction, a, b, a],
+      {b: [Foldable]},
+      [$.Function, a, b, a],
       function(f_, initial, foldable) {
         var f = function(a, b) {
           return f_(a)(b);
@@ -649,8 +733,8 @@
   //. Version of [`reduce`](#reduce) accepting uncurried functions.
   var reduce_ = S.reduce_ =
   def('reduce_',
-      {b: [Z.Foldable]},
-      [$.AnyFunction, a, b, a],
+      {b: [Foldable]},
+      [$.Function, a, b, a],
       Z.reduce);
 
   //# traverse :: (Applicative f, Traversable t) => (a -> f a) -> (a -> f b) -> t a -> f (t b)
@@ -666,8 +750,8 @@
   //. ```
   S.traverse =
   def('traverse',
-      {a: [Z.Traversable], b: [Z.Applicative]},
-      [$.AnyFunction, $.AnyFunction, a, b],
+      {a: [Traversable], b: [Applicative]},
+      [$.Function, $.Function, a, b],
       Z.traverse);
 
   //# ap :: Apply f => f (a -> b) -> f a -> f b
@@ -683,7 +767,7 @@
   //. ```
   var ap = S.ap =
   def('ap',
-      {a: [Z.Apply], b: [Z.Apply], f: [Z.Apply]},
+      {a: [Apply], b: [Apply], f: [Apply]},
       [a, b, c],
       Z.ap);
 
@@ -700,8 +784,8 @@
   //. ```
   var chain = S.chain =
   def('chain',
-      {a: [Z.Chain], b: [Z.Chain]},
-      [$.AnyFunction, a, b],
+      {a: [Chain], b: [Chain]},
+      [$.Function, a, b],
       Z.chain);
 
   //# extend :: Extend e => (e a -> a) -> e a -> e a
@@ -709,7 +793,7 @@
   //. TK.
   S.extend =
   def('extend',
-      {a: [Z.Extend], b: [Z.Extend]},
+      {a: [Extend], b: [Extend]},
       [a, b, b],
       Z.extend);
 
@@ -718,7 +802,7 @@
   //. TK.
   S.extract =
   def('extract',
-      {a: [Z.Extend]},
+      {a: [Extend]},
       [a, b],
       Z.extract);
 
@@ -740,8 +824,8 @@
   //. ```
   S.filter =
   def('filter',
-      {m: [Z.Monad, Z.Monoid]},
-      [$.AnyFunction, m, m],
+      {m: [Monad, Monoid]},
+      [$.Function, m, m],
       Z.filter);
 
   //# reject :: (Monad m, Monoid m a) => (a -> Boolean) -> m a -> m a
@@ -762,8 +846,8 @@
   //. ```
   S.reject =
   def('reject',
-      {m: [Z.Monad, Z.Monoid]},
-      [$.AnyFunction, m, m],
+      {m: [Monad, Monoid]},
+      [$.Function, m, m],
       function(pred, m) {
         return Z.filter(function(x) { return !pred(x); }, m);
       });
@@ -819,7 +903,7 @@
   S.A =
   def('A',
       {},
-      [$.AnyFunction, a, b],
+      [$.Function, a, b],
       function(f, x) { return f(x); });
 
   //# T :: a -> (a -> b) -> b
@@ -838,7 +922,7 @@
   S.T =
   def('T',
       {},
-      [a, $.AnyFunction, b],
+      [a, $.Function, b],
       function(x, f) { return f(x); });
 
   //# C :: (a -> b -> c) -> b -> a -> c
@@ -861,7 +945,7 @@
   S.C =
   def('C',
       {},
-      [$.AnyFunction, b, a, c],
+      [$.Function, b, a, c],
       function(f, x, y) { return f(y)(x); });
 
   //# B :: (b -> c) -> (a -> b) -> a -> c
@@ -878,7 +962,7 @@
   S.B =
   def('B',
       {},
-      [$.AnyFunction, $.AnyFunction, a, c],
+      [$.Function, $.Function, a, c],
       compose3);
 
   //# S :: (a -> b -> c) -> (a -> b) -> a -> c
@@ -896,7 +980,7 @@
   S.S =
   def('S',
       {},
-      [$.AnyFunction, $.AnyFunction, a, c],
+      [$.Function, $.Function, a, c],
       function(f, g, x) { return f(x)(g(x)); });
 
   //. ### Function
@@ -915,7 +999,7 @@
   S.flip =
   def('flip',
       {},
-      [$.AnyFunction, b, a, c],
+      [$.Function, b, a, c],
       function(f, x, y) { return f(y, x); });
 
   //# lift :: Functor f => (a -> b) -> f a -> f b
@@ -931,8 +1015,8 @@
   //. ```
   S.lift =
   def('lift',
-      {a: [Z.Functor], b: [Z.Functor]},
-      [$.AnyFunction, a, b],
+      {a: [Functor], b: [Functor]},
+      [$.Function, a, b],
       map);
 
   //# lift2 :: Apply f => (a -> b -> c) -> f a -> f b -> f c
@@ -955,8 +1039,8 @@
   //. ```
   S.lift2 =
   def('lift2',
-      {a: [Z.Apply], b: [Z.Apply], c: [Z.Apply]},
-      [$.AnyFunction, a, b, c],
+      {a: [Apply], b: [Apply], c: [Apply]},
+      [$.Function, a, b, c],
       function(f, x, y) { return ap(map(f, x), y); });
 
   //# lift3 :: Apply f => (a -> b -> c -> d) -> f a -> f b -> f c -> f d
@@ -973,8 +1057,8 @@
   //. ```
   S.lift3 =
   def('lift3',
-      {a: [Z.Apply], b: [Z.Apply], c: [Z.Apply], d: [Z.Apply]},
-      [$.AnyFunction, a, b, c, d],
+      {a: [Apply], b: [Apply], c: [Apply], d: [Apply]},
+      [$.Function, a, b, c, d],
       function(f, x, y, z) { return ap(ap(map(f, x), y), z); });
 
   //. ### Composition
@@ -997,7 +1081,7 @@
   S.compose =
   def('compose',
       {},
-      [$.AnyFunction, $.AnyFunction, a, c],
+      [$.Function, $.Function, a, c],
       compose3);
 
   //# pipe :: [(a -> b), (b -> c), ..., (m -> n)] -> a -> n
@@ -1018,7 +1102,7 @@
   S.pipe =
   def('pipe',
       {},
-      [$.Array($.AnyFunction), a, b],
+      [$.Array($.Function), a, b],
       function(fs, x) {
         return fs.reduce(function(x, f) { return f(x); }, x);
       });
@@ -1052,7 +1136,7 @@
   S.meld =
   def('meld',
       {},
-      [$.Array($.AnyFunction), $.AnyFunction],
+      [$.Array($.Function), $.Function],
       function(fs) {
         var types = [$.Any];  // return type
         fs.forEach(function(f, idx) {
@@ -1527,7 +1611,7 @@
   var maybe = S.maybe =
   def('maybe',
       {},
-      [b, $.AnyFunction, $Maybe(a), b],
+      [b, $.Function, $Maybe(a), b],
       function(x, f, maybe) { return fromMaybe(x, maybe.map(f)); });
 
   //# justs :: Array (Maybe a) -> Array a
@@ -1564,7 +1648,7 @@
   S.mapMaybe =
   def('mapMaybe',
       {},
-      [$.AnyFunction, $.Array(a), $.Array(b)],
+      [$.Function, $.Array(a), $.Array(b)],
       function(f, xs) { return justs(map(f, xs)); });
 
   //# encase :: (a -> b) -> a -> Maybe b
@@ -1586,7 +1670,7 @@
   var encase = S.encase =
   def('encase',
       {},
-      [$.AnyFunction, a, $Maybe(b)],
+      [$.Function, a, $Maybe(b)],
       function(f, x) {
         try {
           return Just(f(x));
@@ -1603,7 +1687,7 @@
   var encase2 = S.encase2 =
   def('encase2',
       {},
-      [$.AnyFunction, a, b, $Maybe(c)],
+      [$.Function, a, b, $Maybe(c)],
       function(f, x, y) {
         try {
           return Just(f(x)(y));
@@ -1618,7 +1702,7 @@
   S.encase2_ =
   def('encase2_',
       {},
-      [$.AnyFunction, a, b, $Maybe(c)],
+      [$.Function, a, b, $Maybe(c)],
       function(f_, x, y) {
         var f = function(x) {
           return function(y) {
@@ -1636,7 +1720,7 @@
   var encase3 = S.encase3 =
   def('encase3',
       {},
-      [$.AnyFunction, a, b, c, $Maybe(d)],
+      [$.Function, a, b, c, $Maybe(d)],
       function(f, x, y, z) {
         try {
           return Just(f(x)(y)(z));
@@ -1651,7 +1735,7 @@
   S.encase3_ =
   def('encase3_',
       {},
-      [$.AnyFunction, a, b, c, $Maybe(d)],
+      [$.Function, a, b, c, $Maybe(d)],
       function(f_, x, y, z) {
         var f = function(x) {
           return function(y) {
@@ -2110,7 +2194,7 @@
   S.either =
   def('either',
       {},
-      [$.AnyFunction, $.AnyFunction, $Either(a, b), c],
+      [$.Function, $.Function, $Either(a, b), c],
       function(l, r, either) {
         return either.isLeft ? l(either.value) : r(either.value);
       });
@@ -2176,7 +2260,7 @@
   S.encaseEither =
   def('encaseEither',
       {},
-      [$.AnyFunction, $.AnyFunction, a, $Either(l, r)],
+      [$.Function, $.Function, a, $Either(l, r)],
       function(f, g, x) {
         try {
           return Right(g(x));
@@ -2193,7 +2277,7 @@
   var encaseEither2 = S.encaseEither2 =
   def('encaseEither2',
       {},
-      [$.AnyFunction, $.AnyFunction, a, b, $Either(l, r)],
+      [$.Function, $.Function, a, b, $Either(l, r)],
       function(f, g, x, y) {
         try {
           return Right(g(x)(y));
@@ -2209,7 +2293,7 @@
   S.encaseEither2_ =
   def('encaseEither2_',
       {},
-      [$.AnyFunction, $.AnyFunction, a, b, $Either(l, r)],
+      [$.Function, $.Function, a, b, $Either(l, r)],
       function(f, g_, x, y) {
         var g = function(x) {
           return function(y) {
@@ -2227,7 +2311,7 @@
   var encaseEither3 = S.encaseEither3 =
   def('encaseEither3',
       {},
-      [$.AnyFunction, $.AnyFunction, a, b, c, $Either(l, r)],
+      [$.Function, $.Function, a, b, c, $Either(l, r)],
       function(f, g, x, y, z) {
         try {
           return Right(g(x)(y)(z));
@@ -2243,7 +2327,7 @@
   S.encaseEither3_ =
   def('encaseEither3',
       {},
-      [$.AnyFunction, $.AnyFunction, a, b, c, $Either(l, r)],
+      [$.Function, $.Function, a, b, c, $Either(l, r)],
       function(f, g_, x, y, z) {
         var g = function(x) {
           return function(y) {
@@ -2280,9 +2364,8 @@
   //. ### Alternative
 
   //  Alternative :: TypeClass
-  var Alternative = Z.TypeClass(
+  var Alternative = $.TypeClass(
     'Alternative',
-    [],
     function(x) {
       switch (_type(x)) {
         case 'Array':
@@ -2408,7 +2491,7 @@
   S.ifElse =
   def('ifElse',
       {},
-      [$.AnyFunction, $.AnyFunction, $.AnyFunction, a, b],
+      [$.Function, $.Function, $.Function, a, b],
       function(pred, f, g, x) { return pred(x) ? f(x) : g(x); });
 
   //# allPass :: Array (a -> Boolean) -> a -> Boolean
@@ -2428,7 +2511,7 @@
   S.allPass =
   def('allPass',
       {},
-      [$.Array($.AnyFunction), a, $.Boolean],
+      [$.Array($.Function), a, $.Boolean],
       function(preds, x) {
         for (var idx = 0; idx < preds.length; idx += 1) {
           if (!preds[idx](x)) return false;
@@ -2453,7 +2536,7 @@
   S.anyPass =
   def('anyPass',
       {},
-      [$.Array($.AnyFunction), a, $.Boolean],
+      [$.Array($.Function), a, $.Boolean],
       function(preds, x) {
         for (var idx = 0; idx < preds.length; idx += 1) {
           if (preds[idx](x)) return true;
@@ -2848,7 +2931,7 @@
   S.find =
   def('find',
       {},
-      [$.AnyFunction, $.Array(a), $Maybe(a)],
+      [$.Function, $.Array(a), $Maybe(a)],
       function(pred, xs) {
         for (var idx = 0, len = xs.length; idx < len; idx += 1) {
           if (pred(xs[idx])) {
@@ -2897,7 +2980,7 @@
   S.unfoldr =
   def('unfoldr',
       {},
-      [$.AnyFunction, b, $.Array(a)],
+      [$.Function, b, $.Array(a)],
       function(f, x) {
         var result = [];
         var m = f(x);
@@ -3108,7 +3191,7 @@
   //. ```
   S.sum =
   def('sum',
-      {f: [Z.Foldable]},
+      {f: [Foldable]},
       [f, $.FiniteNumber],
       reduce(function(a) { return function(b) { return a + b; }; }, 0));
 
@@ -3187,7 +3270,7 @@
   //. ```
   S.product =
   def('product',
-      {f: [Z.Foldable]},
+      {f: [Foldable]},
       [f, $.FiniteNumber],
       reduce(function(a) { return function(b) { return a * b; }; }, 1));
 
@@ -3225,7 +3308,7 @@
   //. ```
   S.mean =
   def('mean',
-      {f: [Z.Foldable]},
+      {f: [Foldable]},
       [f, $Maybe($.FiniteNumber)],
       function(foldable) {
         var result = reduce_(
diff --git a/package.json b/package.json
index 37a930f1..88a41bcf 100644
--- a/package.json
+++ b/package.json
@@ -11,7 +11,7 @@
     "test": "make lint test"
   },
   "dependencies": {
-    "sanctuary-def": "sanctuary-js/sanctuary-def#dc-sanctuary-type-classes",
+    "sanctuary-def": "0.6.x",
     "sanctuary-type-classes": "sanctuary-js/sanctuary-type-classes#dc-everything"
   },
   "devDependencies": {