LARA This is an old revision of the document! Equality, Undecidable and Decidable FOL Classes Continuation of lecture11. More on Equality Factor Structures Herbrand Universe for Equality Proof Rule for Equality Undecidable and Decidable Classes of FOL Formulas Undecidability of First-Order Logic Finite Models imply Decidability Classical Decision Problem Decidable Exists-Forall Class and its Use Exists-Forall Class Definition Deciding Exists-Forall Class Deciding a Language of Sets and Relations Verifying Programs with Global Containers