The Bedwyr system for model checking over syntactic expressions

TL;DR

The Bedwyr system extends logic programming to enable direct model checking on syntactic expressions with bindings, supporting fixed points and higher-order syntax for advanced reasoning.

Contribution

It introduces a logic programming system in OCaml that incorporates recent proof search advances, enabling model checking on expressions with variable bindings and fixed points.

Findings

Supports model checking on syntactic expressions with bindings

Captures finite success and failure in proof search

Handles higher-order abstract syntax with lambda-binders

Abstract

Bedwyr is a generalization of logic programming that allows model checking directly on syntactic expressions possibly containing bindings. This system, written in OCaml, is a direct implementation of two recent advances in the theory of proof search. The first is centered on the fact that both finite success and finite failure can be captured in the sequent calculus by incorporating inference rules for definitions that allow fixed points to be explored. As a result, proof search in such a sequent calculus can capture simple model checking problems as well as may and must behavior in operational semantics. The second is that higher-order abstract syntax is directly supported using term-level $\lambda$-binders and the $\nabla$ quantifier. These features allow reasoning directly on expressions containing bound variables.