Scheme Formal Verification

Overview

This project bridges the gap between formal specifications in TLA+ and practical Scheme implementations, enabling property-based testing and verification of functional programs.

Key Features

TLA+ to Scheme Translation

• Automatic translation of TLA+ specifications to executable Scheme predicates
• Support for common TLA+ operators and data structures
• Preservation of specification semantics in generated code

Property-Based Testing Framework

• QuickCheck-style property testing for Scheme
• Automatic test case generation from TLA+ invariants
• Shrinking strategies for minimal counterexamples

Verification Workflows

• Integration with existing Scheme development tools
• CI/CD pipeline support for continuous verification
• Incremental verification for large codebases

Technical Approach

The system employs a multi-stage pipeline:

1. Specification Parsing: TLA+ specifications are parsed into an intermediate representation
2. Property Extraction: Invariants and properties are extracted and categorized
3. Code Generation: Scheme test predicates are generated from properties
4. Test Execution: Property-based tests are run with configurable strategies

Example Usage

;; Define a TLA+ specification
(define-tla-spec sorting-spec
  "INVARIANT Sorted(output) /\ Permutation(input, output)")

;; Link to implementation
(verify-against-spec merge-sort sorting-spec)

;; Run verification
(run-verification 'merge-sort 
  #:num-tests 1000
  #:max-size 100)

Research Impact

This work demonstrates that formal methods can be practically integrated into functional programming workflows without sacrificing development velocity. By focusing on property-based testing rather than full formal proofs, we achieve a pragmatic balance between correctness guarantees and implementation effort.

Future Work

• Extension to concurrent and distributed systems
• Integration with SMT solvers for stronger guarantees
• Machine learning approaches to invariant inference
• Support for additional specification languages