# Propositional Proofs

This is continuation of lecture06.

Goals:

- discuss proof systems for propositional logic that are useful for SAT solvers
- further illustrate notions of soundness and completeness of proof systems
- show properties of proof systems on infinite formulas, because they will be useful in first-order logic
- discuss some SAT solving techniques

## Topics

Satisfiability of Sets of Formulas

Definition of Propositional Resolution

Deriving Propositional Resolution

Interpolants from Resolution Proofs

Polynomial Algorithm for Horn Clauses and Boolean Constraint Propagation

Continued in lecture08.