acl2/acl2
Feb 2025 – Mar 2026
12 Months active
Languages Used
Common LispLispPerlLaTeXMakefilelisp
Technical Skills
ACL2Abstract Data TypesBuild SystemCode GenerationDocumentationDomain-Specific Languages
Sol Swords
PROFILE
Sol Swords
Sol Swords contributed to the acl2/acl2 repository by developing and refining advanced formal verification tooling, focusing on symbolic execution, macro systems, and build automation. Over twelve months, Sol engineered features such as enhanced FGL rewriting, robust counterexample generation, and improved visitor and type systems, leveraging Common Lisp and Makefile for both core logic and build infrastructure. Their work emphasized maintainability and reliability, introducing debugging utilities, resource controls, and parallel build support. By integrating formal methods and theorem proving with practical debugging and documentation improvements, Sol delivered deeper reasoning capabilities and more efficient workflows for ACL2 developers and users.
Overall Statistics
Feature vs Bugs
84%Features
Repository Contributions
92Total
Bugs
8
Commits
92
Features
42
Lines of code
23,718,266
Activity Months12
Your Network
564 peopleSame Organization
@arm.com532
Shared Repositories
32
Lottie-uiMember
Aakash KoneruMember
Aakash KoneruMember
Aakash KoneruMember
ACL2 Build ServerMember
Ankit KumarMember
Eric McCarthyMember
Cuong ChauMember
David RussinoffMember
Work History
March 2026
4 Commits • 2 Features
Mar 1, 2026March 2026 focused on strengthening ACL2 theorem proving capabilities and improving developer-facing documentation in acl2/acl2. Key work includes enhancing equality and induction handling, and delivering release notes and documentation clarifications for the FGL and X86ISA libraries. No major bugs fixed this month; emphasis on delivering robust features and improving maintainability through better docs.
4 Commits • 2 Features
Mar 1, 2026March 2026 focused on strengthening ACL2 theorem proving capabilities and improving developer-facing documentation in acl2/acl2. Key work includes enhancing equality and induction handling, and delivering release notes and documentation clarifications for the FGL and X86ISA libraries. No major bugs fixed this month; emphasis on delivering robust features and improving maintainability through better docs.
March 2026
February 2026
6 Commits • 4 Features
Feb 1, 2026February 2026 — ACL2 (acl2/acl2): Strengthened build reliability, debugging capabilities, and metareasoning usability. Delivered parallelism-ready build system, advanced FGL tooling, expanded congruence rules, and a safety-focused rewrite workflow. These changes accelerate development cycles, improve proof automation, and enhance maintainability across core ACL2 components.
February 2026
6 Commits • 4 Features
Feb 1, 2026February 2026 — ACL2 (acl2/acl2): Strengthened build reliability, debugging capabilities, and metareasoning usability. Delivered parallelism-ready build system, advanced FGL tooling, expanded congruence rules, and a safety-focused rewrite workflow. These changes accelerate development cycles, improve proof automation, and enhance maintainability across core ACL2 components.
November 2025
1 Commits
Nov 1, 2025November 2025 (acl2/acl2): Key deliverable was a bug fix to the Typed Sets Intersection Theorem Correctness. Strengthened the logical condition in the rule definition to ensure correct intersection results; committed as 3e1472e9f48404edf29626397438c356401e997a ('FTY osets: strengthen theorem about intersect of typed sets'). Impact: increased reliability of typed-set reasoning in formal proofs and downstream verifications, reducing risk of incorrect results. Skills demonstrated include ACL2 theorem proving, formal verification, precise condition modeling, and disciplined Git workflow.
1 Commits
Nov 1, 2025November 2025 (acl2/acl2): Key deliverable was a bug fix to the Typed Sets Intersection Theorem Correctness. Strengthened the logical condition in the rule definition to ensure correct intersection results; committed as 3e1472e9f48404edf29626397438c356401e997a ('FTY osets: strengthen theorem about intersect of typed sets'). Impact: increased reliability of typed-set reasoning in formal proofs and downstream verifications, reducing risk of incorrect results. Skills demonstrated include ACL2 theorem proving, formal verification, precise condition modeling, and disciplined Git workflow.
November 2025
October 2025
7 Commits • 5 Features
Oct 1, 2025Month: 2025-10 — ACL2 development month focused on performance, robustness, and compatibility improvements in acl2/acl2. Key features delivered: - Unconditional operator and memoization optimization for counterexample creation: introduced unconditional operator to bypass path condition inclusion for IF branches during rewriting, and memoized fgl-object-vars to accelerate counterexample creation for large objects. Commit: 9f704b6e7a75d923d67b8b86d4500c1aecf3d450. - Visitor system type handling improvements: added visitor-remove-types-from-alist, refactored process-defvisitor for correct management of generated type functions and renames, and introduced visitor-types-make-type-graph-top to simplify type graph generation. Commit: 8d753960a2500dd33a3ce7c3da5af9ecd075bc59. - Fine-grained control over counterexample generation: added ct rex-no-implicit macro and adjusted logic to respect per-function counterexample generation rules for more precise control. Commit: b77bb301748e84f7ead7f59b4139c273313acf9e. - SAT checks configuration and splitter merging improvements: introduced new SAT check configuration and refined merging rules for splitters to enhance SAT-related components. Commit: 4663419eac9a10c826b15a42f970a6a53abececb. - Documentation improvements and corrections: corrected wording in IF rules documentation, fixed utility reference naming, and clarified abort-current-rewrite documentation. Commit: 5f2b2b3b8351e79d21188541212af97e39ed3b1d. Major bugs fixed: - Arithmetic rules fix for operands: support :g-integer and :g-concrete types; fixes syntax binding conditions, improving robustness of bitwise operations. Commit: 5489fa25e922caa7f0b2a83f79fcde0d0ef1e8b4. - ACL2(r) compatibility: remove non-ACL2(r) parameters and enforce real-number checks to improve library usability in ACL2(r). Commit: b6ba29dc93a9c9aa4bbfb324ad8c964a6e96f367. Overall impact and accomplishments: - Performance: targeted optimizations (unconditional operator, memoization) reduce counterexample generation time for large objects, accelerating verification cycles. - Robustness: strengthened type handling and graph generation reduces edge-case failures in type analysis and verification flows. - Control and precision: per-function counterexample rules enable more accurate and customizable verification scenarios. - Compatibility and reliability: ACL2(r) compatibility improvements broaden library usability and adoption; SAT-related enhancements improve verification tooling reliability. - Documentation quality: clearer guidance and references reduce onboarding time for new users and contributors. Technologies/skills demonstrated: - FGL optimizations (memoization, operator controls) and rewriting strategies - Visitor pattern usage and type graph tooling - Fine-grained counterexample generation logic - Arithmetic rule robustness for mixed operand types - ACL2(r) compatibility considerations and real-number checks - SAT configuration management and splitter merging - Effective documentation and contributor guidance
October 2025
7 Commits • 5 Features
Oct 1, 2025Month: 2025-10 — ACL2 development month focused on performance, robustness, and compatibility improvements in acl2/acl2. Key features delivered: - Unconditional operator and memoization optimization for counterexample creation: introduced unconditional operator to bypass path condition inclusion for IF branches during rewriting, and memoized fgl-object-vars to accelerate counterexample creation for large objects. Commit: 9f704b6e7a75d923d67b8b86d4500c1aecf3d450. - Visitor system type handling improvements: added visitor-remove-types-from-alist, refactored process-defvisitor for correct management of generated type functions and renames, and introduced visitor-types-make-type-graph-top to simplify type graph generation. Commit: 8d753960a2500dd33a3ce7c3da5af9ecd075bc59. - Fine-grained control over counterexample generation: added ct rex-no-implicit macro and adjusted logic to respect per-function counterexample generation rules for more precise control. Commit: b77bb301748e84f7ead7f59b4139c273313acf9e. - SAT checks configuration and splitter merging improvements: introduced new SAT check configuration and refined merging rules for splitters to enhance SAT-related components. Commit: 4663419eac9a10c826b15a42f970a6a53abececb. - Documentation improvements and corrections: corrected wording in IF rules documentation, fixed utility reference naming, and clarified abort-current-rewrite documentation. Commit: 5f2b2b3b8351e79d21188541212af97e39ed3b1d. Major bugs fixed: - Arithmetic rules fix for operands: support :g-integer and :g-concrete types; fixes syntax binding conditions, improving robustness of bitwise operations. Commit: 5489fa25e922caa7f0b2a83f79fcde0d0ef1e8b4. - ACL2(r) compatibility: remove non-ACL2(r) parameters and enforce real-number checks to improve library usability in ACL2(r). Commit: b6ba29dc93a9c9aa4bbfb324ad8c964a6e96f367. Overall impact and accomplishments: - Performance: targeted optimizations (unconditional operator, memoization) reduce counterexample generation time for large objects, accelerating verification cycles. - Robustness: strengthened type handling and graph generation reduces edge-case failures in type analysis and verification flows. - Control and precision: per-function counterexample rules enable more accurate and customizable verification scenarios. - Compatibility and reliability: ACL2(r) compatibility improvements broaden library usability and adoption; SAT-related enhancements improve verification tooling reliability. - Documentation quality: clearer guidance and references reduce onboarding time for new users and contributors. Technologies/skills demonstrated: - FGL optimizations (memoization, operator controls) and rewriting strategies - Visitor pattern usage and type graph tooling - Fine-grained counterexample generation logic - Arithmetic rule robustness for mixed operand types - ACL2(r) compatibility considerations and real-number checks - SAT configuration management and splitter merging - Effective documentation and contributor guidance
September 2025
11 Commits • 4 Features
Sep 1, 2025Monthly summary for 2025-09 focusing on delivering deeper FGL tracing, robust interpreter state management, and stability improvements across core algorithms and tooling for ACL2. Emphasis on granularity, reliability, and safety in symbolic execution, with tangible business value in debuggability, correctness, and licensing compliance.
11 Commits • 4 Features
Sep 1, 2025Monthly summary for 2025-09 focusing on delivering deeper FGL tracing, robust interpreter state management, and stability improvements across core algorithms and tooling for ACL2. Emphasis on granularity, reliability, and safety in symbolic execution, with tangible business value in debuggability, correctness, and licensing compliance.
September 2025
August 2025
9 Commits • 5 Features
Aug 1, 2025August 2025 monthly summary for acl2/acl2 focused on delivering flexible visitor generation, robust counterexample analysis, interpreter resource controls, and improved tracing for debugging. Highlighted business value includes faster, more reliable symbolic analysis, reduced debugging time, and greater modeling flexibility. Major improvements span feature delivers, bug fixes, and performance tuning across the FGL stack and macro system.
August 2025
9 Commits • 5 Features
Aug 1, 2025August 2025 monthly summary for acl2/acl2 focused on delivering flexible visitor generation, robust counterexample analysis, interpreter resource controls, and improved tracing for debugging. Highlighted business value includes faster, more reliable symbolic analysis, reduced debugging time, and greater modeling flexibility. Major improvements span feature delivers, bug fixes, and performance tuning across the FGL stack and macro system.
July 2025
6 Commits • 2 Features
Jul 1, 2025July 2025 (Month: 2025-07) – ACL2/acl2: Focused on documentation quality, stability, and enabling richer verification capabilities. Key outcomes include: (1) documentation accuracy and internal consistency improvements—corrected docstrings, simplified template iteration logic, fixed breakages from a renamed logsquash-related function in congruences.lisp, and updated FGL docs and timing output for consistency checks; (2) new FTY capabilities—added a :post-acc-events option to deftypes/macros and introduced a new omap fixtype 'map' with a formal fixpoint type and associated equivalence; (3) improved maintainability and reliability through targeted fixes and alignment of documentation with code changes; and (4) established groundwork for enhanced verification workflows and post-accumulator event analysis, reinforcing long-term robustness of the verification toolchain.
6 Commits • 2 Features
Jul 1, 2025July 2025 (Month: 2025-07) – ACL2/acl2: Focused on documentation quality, stability, and enabling richer verification capabilities. Key outcomes include: (1) documentation accuracy and internal consistency improvements—corrected docstrings, simplified template iteration logic, fixed breakages from a renamed logsquash-related function in congruences.lisp, and updated FGL docs and timing output for consistency checks; (2) new FTY capabilities—added a :post-acc-events option to deftypes/macros and introduced a new omap fixtype 'map' with a formal fixpoint type and associated equivalence; (3) improved maintainability and reliability through targeted fixes and alignment of documentation with code changes; and (4) established groundwork for enhanced verification workflows and post-accumulator event analysis, reinforcing long-term robustness of the verification toolchain.
July 2025
June 2025
11 Commits • 5 Features
Jun 1, 2025Month: 2025-06 | ACL2 development highlights focused on advancing rewriting capabilities, performance, reliability, and maintainability within the acl2/acl2 repository. Key work spans FGL rewriting enhancements, constraint processing optimization, math utilities, and framework improvements, together delivering stronger analysis capabilities and faster feedback loops for developers and users. Key outcomes: - FGL rewriting enhancements and debugging tools: Introduced FGL-HIDE and TRIGGER-CONSTRAINTS for symbolic manipulation and added backtrace extraction during rewriting to aid debugging and rule analysis. - FGL constraint processing optimization: Implemented caching of completed Boolean constraint invocations and memoization in the FGL object evaluator to reduce recomputation and accelerate constraint checks. - Counterexample generation bug fix: Corrected counterexample logic to reliably handle structure of associated values, improving correctness of test scenarios and debugging workflows. - Rational and bitwise utilities: Added ratbit-decomp for rational bit decomposition, added a rational-exponent theorem, and introduced bitwise operations like loghead/logsquash to support advanced reasoning. - Defvisitor framework enhancements: Added short-circuiting support and a beta utility to reason about updater visitors, aiding verification and transformation reasoning. Overall impact: The month delivered measurable improvements in debugging capability, performance, and maintainability, with clearer ownership of transformation tooling and stronger correctness in counterexample generation. Technologies/skills demonstrated: Lisp-based tooling for FGL rewriting, memoization techniques, backtrace extraction, rational/bitwise arithmetic utilities, defvisitor patterns, and repository maintenance practices.
June 2025
11 Commits • 5 Features
Jun 1, 2025Month: 2025-06 | ACL2 development highlights focused on advancing rewriting capabilities, performance, reliability, and maintainability within the acl2/acl2 repository. Key work spans FGL rewriting enhancements, constraint processing optimization, math utilities, and framework improvements, together delivering stronger analysis capabilities and faster feedback loops for developers and users. Key outcomes: - FGL rewriting enhancements and debugging tools: Introduced FGL-HIDE and TRIGGER-CONSTRAINTS for symbolic manipulation and added backtrace extraction during rewriting to aid debugging and rule analysis. - FGL constraint processing optimization: Implemented caching of completed Boolean constraint invocations and memoization in the FGL object evaluator to reduce recomputation and accelerate constraint checks. - Counterexample generation bug fix: Corrected counterexample logic to reliably handle structure of associated values, improving correctness of test scenarios and debugging workflows. - Rational and bitwise utilities: Added ratbit-decomp for rational bit decomposition, added a rational-exponent theorem, and introduced bitwise operations like loghead/logsquash to support advanced reasoning. - Defvisitor framework enhancements: Added short-circuiting support and a beta utility to reason about updater visitors, aiding verification and transformation reasoning. Overall impact: The month delivered measurable improvements in debugging capability, performance, and maintainability, with clearer ownership of transformation tooling and stronger correctness in counterexample generation. Technologies/skills demonstrated: Lisp-based tooling for FGL rewriting, memoization techniques, backtrace extraction, rational/bitwise arithmetic utilities, defvisitor patterns, and repository maintenance practices.
May 2025
13 Commits • 4 Features
May 1, 2025Monthly summary for acl2/acl2 - May 2025. This period focused on delivering core FGL enhancements, debugging utilities, and maintainability improvements that reinforce verification capabilities, developer productivity, and codebase health. Key contributions span four areas: FGL improvements (rewriter, annotations, and debug toolkit), FGL debugging enhancements (breadcrumbs and error-handling utilities), Counterexample generation overhaul, and maintenance/documentation updates. Notable work includes binding free variables via path assumptions, new rewriting utilities, updated annotation book, added debug-utils, breadcrumbs in scratch objects, break/stop-on-error utilities, and improved error handling. The counterexample machinery was reworked for clarity and maintainability with explicit data structures and graphs. Maintenance efforts covered build system scanning tweaks and What's New metadata for ACL2-2025 Workshop. Overall, these efforts increase reliability, debuggability, and long-term maintainability while delivering tangible verification improvements.
13 Commits • 4 Features
May 1, 2025Monthly summary for acl2/acl2 - May 2025. This period focused on delivering core FGL enhancements, debugging utilities, and maintainability improvements that reinforce verification capabilities, developer productivity, and codebase health. Key contributions span four areas: FGL improvements (rewriter, annotations, and debug toolkit), FGL debugging enhancements (breadcrumbs and error-handling utilities), Counterexample generation overhaul, and maintenance/documentation updates. Notable work includes binding free variables via path assumptions, new rewriting utilities, updated annotation book, added debug-utils, breadcrumbs in scratch objects, break/stop-on-error utilities, and improved error handling. The counterexample machinery was reworked for clarity and maintainability with explicit data structures and graphs. Maintenance efforts covered build system scanning tweaks and What's New metadata for ACL2-2025 Workshop. Overall, these efforts increase reliability, debuggability, and long-term maintainability while delivering tangible verification improvements.
May 2025
April 2025
13 Commits • 4 Features
Apr 1, 2025April 2025 monthly summary for acl2/acl2 focused on strengthening core transformation reliability, cross-package hinting, and FGL/FTY integration, with new options to manage product counts and type prescriptions. The work delivered deeper let-abstraction handling, more robust hinting, and broader interoperability across the ACL2 ecosystem, while maintaining backward compatibility and non-executable reasoning support.
April 2025
13 Commits • 4 Features
Apr 1, 2025April 2025 monthly summary for acl2/acl2 focused on strengthening core transformation reliability, cross-package hinting, and FGL/FTY integration, with new options to manage product counts and type prescriptions. The work delivered deeper let-abstraction handling, more robust hinting, and broader interoperability across the ACL2 ecosystem, while maintaining backward compatibility and non-executable reasoning support.
March 2025
3 Commits • 2 Features
Mar 1, 2025Monthly work summary for 2025-03 focused on ACL2 repository (acl2/acl2): delivered formal verification enhancements for stobjs and rational-exponent theorems, plus a build system improvement to make parallel builds safer. The work strengthens correctness guarantees in the ACL2 prover and improves build reliability in multi-core environments.
3 Commits • 2 Features
Mar 1, 2025Monthly work summary for 2025-03 focused on ACL2 repository (acl2/acl2): delivered formal verification enhancements for stobjs and rational-exponent theorems, plus a build system improvement to make parallel builds safer. The work strengthens correctness guarantees in the ACL2 prover and improves build reliability in multi-core environments.
March 2025
February 2025
8 Commits • 5 Features
Feb 1, 2025February 2025 monthly summary for acl2/acl2: Delivered key features across FTY usability, macro enhancements, formal verification, build tooling, and abstract stobj support. Included a documentation improvement and groundwork for broader verification and usability gains. This month focused on reducing boilerplate, increasing expressivity of macro patterns, and improving build flexibility.
February 2025
8 Commits • 5 Features
Feb 1, 2025February 2025 monthly summary for acl2/acl2: Delivered key features across FTY usability, macro enhancements, formal verification, build tooling, and abstract stobj support. Included a documentation improvement and groundwork for broader verification and usability gains. This month focused on reducing boilerplate, increasing expressivity of macro patterns, and improving build flexibility.
Activity
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Quality Metrics
Correctness89.4%
Maintainability86.6%
Architecture87.4%
Performance78.2%
AI Usage22.0%
Skills & Technologies
Programming Languages
Common LispLaTeXLispMakefilePerllisp
Technical Skills
ACL2ACL2 Theorem ProvingAbstract Data TypesAlgorithm AnalysisAlgorithm DesignAlgorithm OptimizationAlgorithm RefinementArithmetic RulesBitwise OperationsBug FixingBuild SystemBuild System ConfigurationBuild SystemsCode AnalysisCode Generation
Repositories Contributed To
Overview of all repositories you've contributed to across your timeline