239 research outputs found
Verified AIG Algorithms in ACL2
And-Inverter Graphs (AIGs) are a popular way to represent Boolean functions
(like circuits). AIG simplification algorithms can dramatically reduce an AIG,
and play an important role in modern hardware verification tools like
equivalence checkers. In practice, these tricky algorithms are implemented with
optimized C or C++ routines with no guarantee of correctness. Meanwhile, many
interactive theorem provers can now employ SAT or SMT solvers to automatically
solve finite goals, but no theorem prover makes use of these advanced,
AIG-based approaches.
We have developed two ways to represent AIGs within the ACL2 theorem prover.
One representation, Hons-AIGs, is especially convenient to use and reason
about. The other, Aignet, is the opposite; it is styled after modern AIG
packages and allows for efficient algorithms. We have implemented functions for
converting between these representations, random vector simulation, conversion
to CNF, etc., and developed reasoning strategies for verifying these
algorithms.
Aside from these contributions towards verifying AIG algorithms, this work
has an immediate, practical benefit for ACL2 users who are using GL to
bit-blast finite ACL2 theorems: they can now optionally trust an off-the-shelf
SAT solver to carry out the proof, instead of using the built-in BDD package.
Looking to the future, it is a first step toward implementing verified AIG
simplification algorithms that might further improve GL performance.Comment: In Proceedings ACL2 2013, arXiv:1304.712
Integrating multiple sources to answer questions in Algebraic Topology
We present in this paper an evolution of a tool from a user interface for a
concrete Computer Algebra system for Algebraic Topology (the Kenzo system), to
a front-end allowing the interoperability among different sources for
computation and deduction. The architecture allows the system not only to
interface several systems, but also to make them cooperate in shared
calculations.Comment: To appear in The 9th International Conference on Mathematical
Knowledge Management: MKM 201
Initial Experiments with TPTP-style Automated Theorem Provers on ACL2 Problems
This paper reports our initial experiments with using external ATP on some
corpora built with the ACL2 system. This is intended to provide the first
estimate about the usefulness of such external reasoning and AI systems for
solving ACL2 problems.Comment: In Proceedings ACL2 2014, arXiv:1406.123
Industrial-Strength Documentation for ACL2
The ACL2 theorem prover is a complex system. Its libraries are vast.
Industrial verification efforts may extend this base with hundreds of thousands
of lines of additional modeling tools, specifications, and proof scripts. High
quality documentation is vital for teams that are working together on projects
of this scale. We have developed XDOC, a flexible, scalable documentation tool
for ACL2 that can incorporate the documentation for ACL2 itself, the Community
Books, and an organization's internal formal verification projects, and which
has many features that help to keep the resulting manuals up to date. Using
this tool, we have produced a comprehensive, publicly available ACL2+Books
Manual that brings better documentation to all ACL2 users. We have also
developed an extended manual for use within Centaur Technology that extends the
public manual to cover Centaur's internal books. We expect that other
organizations using ACL2 will wish to develop similarly extended manuals.Comment: In Proceedings ACL2 2014, arXiv:1406.123
Specification of Adleman’s Restricted Model Using an Automated Reasoning System: Verification of Lipton’s Experiment
The aim ofthis paper is to develop an executable prototype
ofan unconventional model ofcomputation. Using the PVS verification
system (an interactive environment for writing formal specifications
and checking formal proofs), we formalize the restricted model, based on
DNA, due to L. Adleman. Also, we design a formal molecular program in
this model that solves SAT following Lipton’s ideas.We prove using PVS
the soundness and completeness ofthis molecular program. This work
is intended to give an approach to the opportunities offered by mechanized
analysis ofuncon ventional model ofcomputation in general. This
approach opens up new possibilities ofv erifying molecular experiments
before implementing them in a laboratory.Ministerio de Educación y Cultura TIC2000-1368-C03-02Ministerio de Educación y Cultura PB96-134
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