On The Unreasonable Effectiveness of Boolean SAT Solvers
University of Waterloo
20 Apr 2018 Friday, 04:00 PM to 05:30 PM
COM1 Level 3
Modern conflict-driven clause-learning (CDCL) Boolean SAT solvers routinely solve very large industrial SAT instances in relatively short periods of time. This phenomenon has stumped both theoreticians and practitioners since Boolean satisfiability is an NP-complete problem widely believed to be intractable. It is clear that these solvers somehow exploit the structure of real-world instances. However, to-date there have been few results that precisely characterize this structure or shed any light on why these SAT solvers are so efficient.
In this talk, I will present results that provide a deeper empirical understanding of why CDCL SAT solvers are so efficient, which may eventually lead to a complexity-theoretic result. Our results can be divided into two parts. First, I will talk about structural parameters that can characterize industrial instances and shed light on why they are easier to solve even though they may contain millions of variables. Second, I will talk about internals of CDCL SAT solvers, and describe why they are particularly suited to solve industrial instances.
Dr. Vijay Ganesh is an associate professor at the University of Waterloo. Prior to joining Waterloo in 2012, he was a research scientist at MIT (2007-2012) and completed his PhD in computer science from Stanford University in 2007. Vijay's primary area of research is the theory and practice of automated mathematical reasoning algorithms aimed at software engineering, formal methods, security, and mathematics. In this context he has led the development of many SAT/SMT solvers, most notably, STP, Z3 string, MapleSAT, and MathCheck. He has also proved several decidability and complexity results in the context of the satisfiability problem for various mathematical theories. He has won over 25 awards, honors, and medals to-date for his research, including an ACM Test of Time Award at CCS 2016, an Ontario Early Researcher Award 2016, two Google Faculty Research Awards in 2011 and 2013, and a Ten-Year Most Influential Paper citation at DATE 2008.