Introduction

Abstract

Formal Logic investigates how assertions are combined and connected, how theorems formally can be deduced from certain axioms, and what kind of object a proof is. In Logic there is a consequent separation of syntactical notions (formulas, proofs) — these are essentially strings of symbols built up according to certain rules — and semantical notions (truth values, models) — these are “interpretations”, assignments of “meanings” to the syntactical objects.