zoukankan      html  css  js  c++  java
  • Discrete Mathematics and Its Applications | 1 CHAPTER The Foundations: Logic and Proofs | 1.3 Propositional Equivalences

    DEFINITION 1

    A compound proposition that is always true,no matter what the truth values of the proposi-tional variables that occur in it, is called atautology.

    A compound proposition that is always false iscalled a contradiction.

    A compound proposition that is neither a tautology nor a contradiction is called contingency.

    Logical Equivalences

    Compound propositions that have the same truth values in all possible cases are called logically equivalent.

    DEFINITION 2

    The compound propositions p and q are called logically equivalent if p ↔ q is a tautology.

    The notation p ≡ q denotes that p and q are logically equivalent.

    In general, 2**n rows are required if a compound proposition involves n propositional variables.

     

  • 相关阅读:
    数据库设计——多表之间的关系
    约束
    DQL
    DML
    DDL
    Mysql——基础
    IT大牛关注链接
    deepin20安装Python3.85
    Python中的模块
    python中的装饰器
  • 原文地址:https://www.cnblogs.com/minost/p/10816510.html
Copyright © 2011-2022 走看看