On solving word equations using SAT
conference contributionposted on 21.07.2021, 13:08 authored by Joel DayJoel Day, Thorsten Ehlers, Mitja Kulczynski, Florin Manea, Dirk Nowotka, Danny Bøgsted Poulsen
We present Woorpje, a string solver for bounded word equations (i.e., equations where the length of each variable is upper bounded by a given integer). Our algorithm works by reformulating the satisfiability of bounded word equations as a reachability problem for nondeterministic finite automata, and then carefully encoding this as a propositional satisfiability problem, which we then solve using the well-known Glucose SAT-solver. This approach has the advantage of allowing for the natural inclusion of additional linear length constraints. Our solver obtains reliable and competitive results and, remarkably, discovered several cases where state-of-the-art solvers exhibit a faulty behaviour.
DFG grant MA 5725/2-1
BMBF through the ARAMiS2 (01IS160253) project
- Computer Science