Optimizing SAT Solutions: Maximization and Minimization Approaches in Graph Theory
This project, supervised by Prof. Yoram Moses and Liat Atsmon, explores solving optimization problems through SAT reduction. The key focus is on the Maximal Acyclic Subgraph (MAS) problem, which seeks the maximal weighted subgraph without cycles from a given directed graph. Using the MiniSat SAT-solver, known for its efficiency and open-source nature, the project comprises three parts: verifying equations, optimizing binary expressions, and calculating the Maximal Acyclic Subgraph. The findings contribute to advancements in SAT-solving techniques applied to graph theory.
Optimizing SAT Solutions: Maximization and Minimization Approaches in Graph Theory
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Presentation Transcript
Sat solving maximization and minimization problems • Student: Victoria Kravchenko Supervisors: Prof. Yoram Moses LiatAtsmon The Project Goal Study and evaluate the approach of solving optimization problems through SAT reduction, and using SAT solvers to solve the reduced problems. Maximal Acyclic Subgraph (MAS) This is the problem of finding the maximal weighted (maximal sum of the vertices’ weights) subgraph of the given graph which has no cycles. For example: The MiniSat A SAT-Solver Developed at 2003 by NiklasEén and NiklasSörensson. Its advantages are: • Open-source – easy to work with. • Small – only some hundreds of code lines • Successful – was awarded in the three“industrial” categories and one of the"crafted" categories of the SAT 2005 competition. The project parts: Part 1 – Equation Checker Input: three decimal numbers X,Y,Z Output: whether X+Y=Z Part 2 - SAT with Optimization Input: a vector of binary bits and a binary expression using these bits Output: values for the vector which satisfy the expression such that the vector, as a binary number, is the largest possible Part 3 - Maximal Acyclic Subgraph Input: a directed graph Output: the Maximal Acyclic Subgraph of the given graph. This part uses the ideas of the previous two, in order to solve the Maximal Acyclic Subgraph (MAS) problem by performing reduction to the SAT problem and solving the created problem using the MiniSat. Results: 1 (1) 1 (1) 2 (2) 3 (2) 2 (2) 3 (2) 4 (3) 5 (3) 4 (3) 5 (3)