Tuesday, November 28, 2006

Truth Table for Implication

I was surprised the binary implication operator (→), also called the conditional, has a truth table, just as the AND and OR logical operators do. It is as follows:

A B (A→B)
0 0 1
0 1 1
1 0 0
1 1 1

That is, we can only say something about B if A is true. There is a similar table for the binary biconditional operator (↔):

A B (A↔B)
0 0 1
0 1 0
1 0 0
1 1 1

This means we can determine truth tables for compound statements such as A→(B→C).