Verified AIG Algorithms in ACL2

Add to your list(s) Download to your calendar using vCal

• Jared Davis - Centaur Technologies and UT Austin
• Tuesday 02 April 2013, 13:00-14:00
• Computer Laboratory, William Gates Building, Room SS03.

If you have a question about this talk, please contact William Denman.

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.

This talk is part of the Computer Laboratory Automated Reasoning Group Lunches series.

This talk is included in these lists:

• All Talks (aka the CURE list)
• Cambridge talks
• Computer Laboratory Automated Reasoning Group Lunches
• Computer Laboratory, William Gates Building, Room SS03
• Department of Computer Science and Technology talks and seminars
• Interested Talks
• School of Technology
• Trust & Technology Initiative - interesting events
• bld31
• yk373's list

Note that ex-directory lists are not shown.