CaDiCaL 3.0

Factoring Learned Clauses

This paper revisits previous work on ER, which factors out repeated parts of learned clauses during conflict analysis, and explores how their original strategy benefits from 15 years of improvements in the state-of-the-art solver CaDiCaL, and proposes a new, less intrusive inprocessing approach based on factoring XOR and ITE gates from learned clauses globally.

A Modern View on MCSat

The Model Constructing Satisfiability (MCSat) approach has shown strong performance in solving complex SMT problems, in particular in algebraic SMT theories such as non-linear integer and real arithmetic. In this paper we revisit the theory-independent MCSat framework as a proof system to provide a modern perspective that refines the original formulation of MCSat. By closely formalizing the implementation of MCSat within the Yices2 SMT solver, we incorporate design decisions that diverge from those in the seminal MCSat paper and thereby capture the current state-of-the-art in MCSat-based SMT reasoning. We present a general, theory-agnostic rule scheme for MCSat and instantiate it for several theories, including propositional logic, non-linear real arithmetic, and uninterpreted functions. We provide several detailed examples to illustrate the applicability of the presented calculus.

Conditional Autarkies: Hard Formulas Made Easy

WhyUnsat: A Practical Explanation Tool

Here it is explained how and why the WhyUnsat approach is now also directly applicable, at no implementation cost, to IPASIR-UP-based constraint programming by Lazy Clause Generation (LCG) as well as to SAT Modulo Theories (SMT).

Lazy clause generation in retrospect

This review considers how LCG has been refined and expanded over the years since its invention, and how it is used in all most performant CP solvers.

A Natively Parallel Proof Framework for Clause-Sharing SAT Solving

PalRUP is introduced – an LRUP -based proof format and a bottleneck-free, decentralized parallel checking procedure that only uses the (parallel) file system and is composed of a set of small, sequential trusted components.