Overview on Leo-ii Leo-ii and Tptp

LEO-II is a standalone, resolution-based higher-order theorem prover that is designed for fruitful cooperation with specialist provers for first-order and propositional logic. The idea is to combine the strengths of the different systems. On the other hand, LEO-II itself, as an external reasoner, wants to support interactive proof assistants such as Isabelle/HOL, HOL, and OMEGA by efficiently automating subproblems and thereby reducing user effort. LEO-II predominantly addresses higher-order aspects in its reasoning process with the aim to quickly remove higher-order clauses from the search space and to turn them into essentially first-order clauses which can then be refuted with a first-order prover. For this LEO-II cooperates with the first-order theorem provers E, Spass or Vampire.