- What is a semantic tableau and what is the main advantage of using it to determine if a formula is satisfiable? - Theorem 2.60 in our textbook states: A set of literals is satisfiable if and only if it does not contain a complementary pair of literals. Discuss and illustrate with examples the meaning of this theorem. (note: a literal is a propositional variable or a negation of a propositional variable) - Discuss the algorithm for the construction of a semantic tableau for a formula in propositional logic. What is the main idea of the algorithm? - Show and discuss examples of the use of semantic tableaux.