Some Experiments with Twee-Style Goal-Directedness

In saturation-based theorem proving, selecting the next clause for processing is a major concern. Twee has successfully applied the idea of preferring clauses that share terms with the conjecture by adding equational definitions to transform the problem. In this paper, we apply the idea to the full first-order case, and offer an alternative implementation based on shared terms. Both approaches have complementary applications and show very promising results.