High Quality Content by WIKIPEDIA articles! Larch Prover, or LP for short, is an interactive theorem proving system for multisorted first-order logic. It is currently used at MIT and elsewhere to reason about designs for circuits, concurrent algorithms, hardware, and software. Unlike most theorem provers, which attempt to find proofs automatically for correctly stated conjectures, LP is intended to assist users in finding and correcting flaws in conjectures — the predominant activity in the early stages of the design process.