example of tautology

An example of a tautology and how to test it is given in the truth table below for the statement $(P\vee Q)\vee (\mathrm{\neg }P\wedge \mathrm{\neg }Q)$

$P$	$Q$	$\mathrm{\neg }P\wedge \mathrm{\neg }Q$	$P\vee Q$	$(P\vee Q)\vee (\mathrm{\neg }P\wedge \mathrm{\neg }Q)$
F	F	T	F	T
F	T	F	T	T
T	F	F	T	T
T	T	F	T	T

Thus for whatever truth values P and Q take on, the statement always comes out true as shown in the last coloumn of the truth table.

Title	example of tautology
Canonical name	ExampleOfTautology
Date of creation	2013-03-22 15:27:38
Last modified on	2013-03-22 15:27:38
Owner	bloftin (6104)
Last modified by	bloftin (6104)
Numerical id	4
Author	bloftin (6104)
Entry type	Example
Classification	msc 03B05
Classification	msc 03B10