Plingeling

Plingeling is a parallel SAT solver designed to solve Boolean satisfiability problems by running multiple solver instances in parallel on multi-core processors. It is part of the Lingeling family of SAT solvers and is named to indicate its parallel operation. The approach combines a portfolio of different solver configurations and sometimes different underlying solvers to tackle instances that are difficult for any single solver.

Development and design: Plingeling was created by Armin Biere and collaborators as an extension of Lingeling. It adopts the parallel portfolio strategy, dispatching several solver processes to work on the same problem concurrently. The solvers may include variations of Lingeling and other compatible SAT solvers. Learned clauses can be shared among the different solvers to accelerate progress, though sharing policies vary to control memory use.

Usage and impact: Plingeling is used in SAT research and in solving hard benchmark instances. It has been used in SAT competitions and in practice to improve solving performance on multicore hardware.

Architecture: It runs on multi-core architectures, uses asynchronous communication, reduces redundancy, and uses clause sharing to propagate useful learned information. It is typically invoked as a single executable that orchestrates multiple underlying solvers.

Availability: Plingeling is open-source software and is publicly available, with documentation and source code hosted on public repositories.