• Publications
  • Influence
Generic ILP versus specialized 0-1 ILP: an update
Optimized solvers for the Boolean Satisfiability (SAT) problem have many applications in areas such as hardware and software verification, FPGA routing, planning, etc. Further uses are complicated byExpand
Solving difficult SAT instances in the presence of symmetry
TLDR
An improved construction of symmetry-breaking clauses is proposed and applied to achieve significant speed-ups over current state-of-the-art in Boolean satisfiability and it is shown that in structured SAT instances difficulty may be associated with large numbers of symmetries. Expand
PBS: A Backtrack-Search Pseudo-Boolean Solver and Optimizer
TLDR
This work extends the basic Davis-Putnam framework to handle counting constraints and apply it to solve routing problems, and solves instances of the Max-ONEs optimization problem which seeks to maximize the number of “true” values over all satisfying assignments. Expand
Solving difficult instances of Boolean satisfiability in the presence of symmetry
TLDR
This paper articulates SAT instances that are unusually difficult for their size, including satisfiable instances derived from very large scale integration (VLSI) routing problems and proposes a scheme for fast "opportunistic" symmetry extraction and shows that considerations of symmetry may lead to more efficient reductions to SAT in the VLSI routing domain. Expand
Generic ILP versus specialized 0-1 ILP: an update
TLDR
This work solves instances of the Max-SAT and Max-ONEs optimization problems which seek to maximize the number of satisfied clauses and the "true" values over all satisfying assignments, respectively and shows that specialized 0-1 techniques tend to outperform generic ILP techniques on Boolean optimization problems as well as on general EDA SAT problems. Expand
Breaking instance-independent symmetries in exact graph coloring
TLDR
This work compares several avenues for symmetry-breaking, in particular when certain kinds of symmetry are present in all generated instances, and concludes that instance-independent symmetries should often be processed together with instance-specific asymmetries rather than earlier, at the specification level. Expand
Automatically Exploiting Symmetries in Constraint Programming
TLDR
This work introduces a framework for studying and solving a class of CSP formulations that generalizes earlier work on symmetries in SAT and 0-1 ILP problems, and shows substantial speedups with symmetry-breaking, especially on unsatisfiable instances. Expand
ShatterPB: symmetry-breaking for pseudo-Boolean formulas
Many important tasks in circuit design and verification can be performed in practice via reductions to Boolean Satisfiability (SAT), making SAT a fundamental EDA problem. However such reductionsExpand
Breaking instance-independent symmetries in exact graph coloring
Code optimization and high level synthesis can be posed as constraint satisfaction and optimization problems, such as graph coloring used in register allocation. Naturally-occurring instances of suchExpand
Solution and Optimization of Systems of Pseudo-Boolean Constraints
TLDR
The experimental results show that specialized 0-1 techniques implemented in PBS tend to outperform generic ILP techniques on Boolean optimization problems, as well as on general EDA SAT problems. Expand
...
1
2
...