First Order Logic

Chenkai Wang

0. Introduction

Mathematics is all about logic. Every insightful mathematical theory (among non-mathematical ones) is built up axiomatically. The rules which enable us to produce a theory system are introduced by formal theory. Don't mix formal theory with the actual theory you are playing with! We sometimes call formal theory a metatheory.

1. The Language

2. Some Useful Metatheorems

3. miscellanea

"SUCH THAT" is confusing!