{log}: From a Constraint Logic Programming Language to a Formal Verification Tool

TL;DR

This paper presents a comprehensive formal verification environment built on a Constraint Logic Programming language called {log}, which supports set theory, state machine modeling, automated verification, and test case generation.

Contribution

It introduces an integrated environment that transforms {log} from a CLP language into a unified system for programming and formal verification of state machines.

Findings

{log} can be used as a declarative set-based programming language.

The environment supports automated verification and test case generation for state machines.

State machines serve as both programs and specifications in the system.

Abstract

{log} (read 'setlog') was born as a Constraint Logic Programming (CLP) language where sets and binary relations are first-class citizens, thus fostering set programming. Internally, {log} is a constraint satisfiability solver implementing decision procedures for several fragments of set theory. Hence, {log} can be used as a declarative, set, logic programming language and as an automated theorem prover for set theory. Over time {log} has been extended with some components integrated to the satisfiability solver thus providing a formal verification environment. In this paper we make a comprehensive presentation of this environment which includes a language for the description of state machines based on set theory, an interactive environment for the execution of functional scenarios over state machines, a generator of verification conditions for state machines, automated verification of state machines, and test case generation. State machines are both, programs and specifications; exactly the same code works as a program and as its specification. In this way, with a few additions, a CLP language turned into a seamlessly integrated programming and automated proof system.