by Albert Major

Introduction to Logic

First Order Logic (FOL) Building Blocks

FOL allows us to capture more structure than Truth-Functional Logic (TFL)

FOL has six kinds of symbols:

• (Terms):
  • Names: a, b, c,...r
  • Variables: s, ... x, y, z
• Predicates: A, B, C...
• Connectives: ¬, ∧, ∨, →
• Brackets: (, )
• Quantifiers: ∃, Ɐ

Terms

There are two types of (English) terms:

• A singular term is a word/phrase that refers to a specific entity
• A general term picks out a kind or type

There are two broad types of singular terms

• Proper names pick out specific entities without describing them
• Definite Descriptions pick out specific entities via a description that only they satisfy