date: 2023-12-23
title: propositional-equivalence
status: DONE
author:
  - AllenYGY
tags:
  - Propositional-Equivalence
  - DiscreteStructure
  - Lec2
  - NOTE
created: 2023-12-23T02:12
updated: 2024-04-08T19:38
publish: True
propositional-equivalence
Tautology
- Tautology(恒真)
- contradiction(矛盾)
- contingency(偶然)
Logical Equivalence
- Two propositions (P,Q) are equivalent if the proposition 
- If two propositions are equivalent, they must have the same truth table.
 
Laws
- Identity(同一) laws  
- Domination(支配) laws
- Idempotent (幂等) laws
- Double negation laws