We show how Symbolic Execution can be understood as a variant of the DPLL(T ) algorithm, which is the dominant technique for the Satisfiability Modulo Theories (SMT) problem. In other words, Symbolic Executors are SMT solvers. This view enables us to use an SMT solver, with the ability of generating all models with respect to a set of Boolean atoms, to explore all symbolic paths of a program. T...

Abstract The stability of the entire base station depends on synchronization station’s clock. clock management chip 8A34002 supports SyncE Ethernet and IEEE 1588. In this architecture, GPS receiver, SSI, master/slave switching device all emit PPS/TOD signals. signals are input into FPGA, which outputs one signal. signal enters in design scheme, DPLL provides filtering clock-following output. 8A...

In many theorem proving applications, a proper treatment of equational theories or equality is mandatory. In this paper we show how to integrate a modern treatment of equality in the Model Evolution calculus (ME), a firstorder version of the propositional DPLL procedure. The new calculus, MEE, is a proper extension of the ME calculus without equality. Like ME it maintains an explicit candidate ...

Binary clause reasoning has found some successful applications in SAT, and it is natural to investigate its use in various extensions of SAT. In this paper we investigate the use of binary clause reasoning in the context of solving Quantified Boolean Formulas (QBF). We develop a DPLL based QBF solver that employs extended binary clause reasoning (hyper-binary resolution) to infer new binary cla...

A fruitful connection between algorithm design and proof complexity is the formalization of the DPLL approach to satisfiability testing in terms of tree-like resolution proofs. We consider extensions of the DPLL approach that add some version of memoization, remembering formulas the algorithm has previously shown unsatisfiable. Various versions of such formula caching algorithms have been sugge...

We extend the DPLL(T) framework for satisfiability modulo theories to address richer theories by means of increased flexibility in the interaction between the propositional and theory-specific solvers. We decompose a rich theory into a chain of increasingly more complex subtheories, and define a corresponding propagation strategy which favors the simpler subtheories using two mechanisms. First,...

Most state-of-the-art SAT solvers are based on DPLL search and require the input formula to be in clausal form (cnf). However, typical formulas that arise in practice are non-clausal. We present a new non-clausal SAT-solver based on General Matings instead of DPLL search. Our technique is able to handle non-clausal formulas involving ∧,∨,¬ operators without destroying their structure or introdu...

Learning useful information when solving SAT or CSP problems to speed up a tree-search approaches, is one of the main explored tracks in various works. Such information are known as goods and nogoods and they aim to forbid to repetitively visit the same parts of the search space. Unfortunately and unlike nogoods, the exploitation of goods is limited to tree-search approaches based on the struct...

Search restarts have shown great potential in speeding up SAT solvers based on the DPLL procedure. However, most restart policies presented so far do not take the problem structure into account. In this paper we present several new problem-sensitive restart heuristics. They all observe different search parameters like conflict level or backtrack level over time and, based on their development, ...

Unit propagation-based (UP) lower bounds are used in the vast majority of current Max-SAT solvers. However, lower bounds based on UP have seldom been applied in PseudoBoolean Optimization (PBO) algorithms derived from the DPLL procedure for Propositional Satisfiability (SAT). This paper enhances a DPLL-style PBO algorithm with an UP lower bound, and establishes conditions that enable constraint...