Title
Boolean satisfiability with transitivity constraints
Abstract
We consider a variant of the Boolean satisfiability problem where a subset ϵ of the propositional variables appearing in formula Fsat encode a symmetric, transitive, binary relation over N elements. Each of these relational variables, ei,j, for 1 ≤ i j ≤ N, expresses whether or not the relation holds between elements i and j. The task is to either find a satisfying assignment to Fsat that also satisfies all transitivity constraints over the relational variables (e.g., e1,2 ∧ e2,3 ⇒ e1,3), or to prove that no such assignment exists. Solving this satisfiability problem is the final and most difficult step in our decision procedure for a logic of equality with uninterpreted functions. This procedure forms the core of our tool for verifying pipelined microprocessors.To use a conventional Boolean satisfiability checker, we augment the set of clauses expressing Fsat with clauses expressing the transitivity constraints. We consider methods to reduce the number of such clauses based on the sparse structure of the relational variables.To use Ordered Binary Decision Diagrams (OBDDs), we show that for some sets ϵ, the OBDD representation of the transitivity constraints has exponential size for all possible variable orderings. By considering only those relational variables that occur in the OBDD representation of Fsat, our experiments show that we can readily construct an OBDD representation of the relevant transitivity constraints and thus solve the constrained satisfiability problem.
Year
DOI
Venue
2000
10.1145/566385.566390
ACM Transactions on Computational Logic (TOCL)
Keywords
DocType
Volume
satisfiability problem,elements i,decision procedure,relevant transitivity constraint,conventional boolean satisfiability checker,obdd representation,relational variable,boolean satisfiability problem,boolean satisfiability,decision procedures,binary relation,transitivity constraint,formal verification
Conference
3
Issue
ISBN
Citations 
4
3-540-67770-4
55
PageRank 
References 
Authors
3.96
14
2
Name
Order
Citations
PageRank
Randal E. Bryant192041194.64
Miroslav N. Velev295360.17