A Rust implementation of the syntax of First Order Logic, and a logical 'harness' for making self-consistent logical assertions on a domain of discourse.
Goals:
- Construct and manipulate logical statements using the syntax of first-order logic.
- Define, and make assertions on, predicates and functions with self-consistent logical checking
- Expose an interface for integrating packages that implement (independent of this package) higher-level mathematical concepts (such as set theory) and interfacing with them through the language of FOL.
Non-goals:
- Implement any formalism of set theory, or expose the idea of a set.
- Automated theorem proving
- Provide a base on which higher-level mathematical packages can be implemented.
| Feature | Description | Status |
|---|---|---|
| Logical Syntactics | ||
| FOL grammar | A typed grammar for FOL | ✅ |
| Prenex Normal Form | A typing for PNF and conversion from others forms | ✅ |
| Skolem Normal Form | A typing for SNF and and conversion from other forms | ✅ |
| Conjunctive Normal Form | A typing for CNF and conversion from other forms | ✅ |
| Logical Semantics | ||
| Predicates | Graph support for asserting logical predicates | WIP |
| Functions | Graph support for defining logical functions | WIP |
| Bound Variables | Graph support for creating named bound variables | WIP |
| Logical sentence integration | The ability to directly apply syntactic statements to the FOL graph | Future |
Defines a strongly-typed grammar for first-order logic, together with a set of strongly-typed normal forms, and methods for converting between them.
Defines an in-memory graph structure that keeps track of logical statements and allows for self-consistent logical checking.
The graph is rarely operated on directly but is managed by the public interface created by the many default predicates and functions.