1. What is First-Order Logic (FOL)

1.1 v.s. Propositional Logic

1.2 Introduction of First-Order Logic

First Order Logic := Propositional Logic + :

Example: Not all birds can fly

1.3 Syntax of FOL

Terms are strings:

$$ t::= x\ |\ c\ |\ f(t_1,...,t_n) $$