The Eos SMT/SMA-solver: a preliminary report

This is a preliminary report of work in progress on the development of the Eos SMT/SMA-solver. Eos is the first solver built from the start based on the CDSAT (Conflict-Driven SATisfiability) paradigm for solving satisfiability problems modulo theories and assignments. The latter means that assignments to first-order terms may appear in the input. CDSAT generalizes MCSAT (Model-Constructing SATisfiability), hence CDCL (Conflict-Driven Clause Learning), to theory combination. CDSAT reasons in a union of theories by combining in a conflict-driven manner theory inference systems, called theory modules. The current version of Eos has modules for propositional logic, equality with uninterpreted function symbols (UF), and linear real arithmetic. The module for propositional logic is a MiniSAT-inspired SAT solver. A key feature of MCSAT/CDSAT is theory conflict explanation by theory inferences: to this end, the Eos module for UF applies congruence closure inferences, and the Eos module for real arithmetic uses Fourier-Motzkin resolution; both rules may generate new (i.e., non-input) literals. The core solver in Eos implements the CDSAT transition system and several heuristics used in state-of-the-art CDCL-based SAT solvers. Some of these heuristics (e.g., random restarts) can be reused directly in the context of CDSAT, while others are adapted. Eos employs a generalization of the VSIDS heuristics to make decisions on both propositional and first-order terms, and the watched literals scheme for both BCP (Boolean Constraint Propagation) and deductions involving arithmetic terms and uninterpreted terms

Bargaining and Influence in Conflict Situations

[Excerpt] This chapter examines bargaining as an influence process through which actors attempt to resolve a social conflict. Conflict occurs when two or more interdependent actors have incompatible preferences and perceive or anticipate resistance from each other (Blalock 1989; Kriesberg 1982). Bargaining is a basic form of goal-directed action that involves both intentions to influence and efforts by each actor to carry out these intentions. Tactics are verbal and/or nonverbal actions designed to maneuver oneself into a favorable position vis-a-vis another or to reach some accommodation. Our treatment of bargaining subsumes the concept of negotiation (see Morley and Stephenson 1977). This chapter is organized around a conceptual framework that distinguishes basic types of bargaining contexts. We begin by introducing the framework and then present an overview of and analyze theoretical and empirical work on each type of bargaining context

An Overview of Backtrack Search Satisfiability Algorithms

Propositional Satisfiability (SAT) is often used as the underlying model for a significan

Stratway: A Modular Approach to Strategic Conflict Resolution

In this paper we introduce Stratway, a modular approach to finding long-term strategic resolutions to conflicts between aircraft. The modular approach provides both advantages and disadvantages. Our primary concern is to investigate the implications on the verification of safety-critical properties of a strategic resolution algorithm. By partitioning the problem into verifiable modules much stronger verification claims can be established. Since strategic resolution involves searching for solutions over an enormous state space, Stratway, like most similar algorithms, searches these spaces by applying heuristics, which present especially difficult verification challenges. An advantage of a modular approach is that it makes a clear distinction between the resolution function and the trajectory generation function. This allows the resolution computation to be independent of any particular vehicle. The Stratway algorithm was developed in both Java and C++ and is available through a open source license. Additionally there is a visualization application that is helpful when analyzing and quickly creating conflict scenarios

Matching bias in syllogistic reasoning: Evidence for a dual-process account from response times and confidence ratings

We examined matching bias in syllogistic reasoning by analysing response times, confidence ratings, and individual differences. Roberts’ (2005) “negations paradigm” was used to generate conflict between the surface features of problems and the logical status of conclusions. The experiment replicated matching bias effects in conclusion evaluation (Stupple & Waterhouse, 2009), revealing increased processing times for matching/logic “conflict problems”. Results paralleled chronometric evidence from the belief bias paradigm indicating that logic/belief conflict problems take longer to process than non-conflict problems (Stupple, Ball, Evans, & Kamal-Smith, 2011). Individuals’ response times for conflict problems also showed patterns of association with the degree of overall normative responding. Acceptance rates, response times, metacognitive confidence judgements, and individual differences all converged in supporting dual-process theory. This is noteworthy because dual-process predictions about heuristic/analytic conflict in syllogistic reasoning generalised from the belief bias paradigm to a situation where matching features of conclusions, rather than beliefs, were set in opposition to logic