Consul: a parallel constraint language

The author describes a constraint-based language, Consul, that can exploit implicit parallelism. The results are reported of the first stage of the Consul project, which was designed to produce empirical evidence for or against Consul as a parallel language. To produce the evidence, a parallel-execution model is developed that is based on local propagation and uses some important generalizations of earlier work on local propagation. A set of tools was developed to measure the execution of several Consul programs. The results suggest that considerable parallelism is available in Consul programs and that local propagation is a viable mechanism for solving most real-world constraints. The Consul programs demonstrate that programmers can control performance through the proper choice of algorithms, despite Consul´s declarative nature.<>