From 028c791fa609c2546495a78661503d432470d04c Mon Sep 17 00:00:00 2001 From: Tammy Lee Date: Thu, 18 Oct 2018 19:53:56 -0700 Subject: [PATCH] Added how to prove statements --- .../logic/conditional-and-biconditional-statements/index.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/guide/english/logic/conditional-and-biconditional-statements/index.md b/guide/english/logic/conditional-and-biconditional-statements/index.md index c16bf0733f..3afb11139b 100644 --- a/guide/english/logic/conditional-and-biconditional-statements/index.md +++ b/guide/english/logic/conditional-and-biconditional-statements/index.md @@ -3,6 +3,6 @@ title: Conditional and Biconditional Statements --- ## Conditional and Biconditional Statements -**Conditional statement:** "if". If one thing is true, then something else is true or can happen. *Example:* if it rains right now, then the ground will be wet. *However*, the converse ("if the ground is wet, then it is raining") is not necessarily true. +**Conditional statement:** "if". If one thing is true, then something else is true or can happen. *Example:* if it rains right now, then the ground will be wet. *However*, the converse ("if the ground is wet, then it is raining") is not necessarily true. Let the conditional statement be *"if P, then Q"*. We can use the direct method for proving the conditional statement. First, assume that *P* is true, and then show that *P* ensures that *Q* is true. -___Bi___**conditional statement:** "if and only if". If one thing is true, then something else is true; and if that something else is true, then that the one thing is true. Another way to think about it is that two things are either both true, or both false (not one true and the other false). *Example:* A square has an area of 16 cubic meters if and only if its sides are both 4 meters long. +___Bi___**conditional statement:** "if and only if". If one thing is true, then something else is true; and if that something else is true, then that the one thing is true. Another way to think about it is that two things are either both true, or both false (not one true and the other false). *Example:* A square has an area of 16 cubic meters if and only if its sides are both 4 meters long. When proving biconditional statements, we must prove both directions.