HoIce: An ICE-Based Non-linear Horn Clause Solver

The ICE framework is a machine-learning-based technique originally introduced for inductive invariant inference over transition systems, and building on the supervised learning paradigm. Recently, we adapted the approach to non-linear Horn clause solving in the context of higher-order program verification. We showed that we could solve more of our benchmarks (extracted from higher-order program verification problems) than other state-of-the-art Horn clause solvers. This paper discusses some of the many improvements we recently implemented in HoIce, our implementation of this generalized ICE framework.