# Truth table

• Nov 25th 2009, 11:48 AM
novice
Truth table
$\begin{array}{ccc}P&Q&P \vee Q\\
\hline\\
T&F&T\\
F&T&T\end{array}$

I have looked for an explanation from many books, but none explained why $P\vee Q$ is true.

Can any explain?
• Nov 25th 2009, 12:04 PM
Plato
Quote:

Originally Posted by novice
$\begin{array}{ccc}P&Q&P \vee Q\\
\hline\\
T&F&T\\
F&T&T\end{array}$

I have looked for an explanation from many books, but none explained why $P\vee Q$ is true.

Can any explain?

$\begin{array}{ccc}P&Q&P \vee Q\\
T&T&T\\
T&F&T\\
F&T&T\\
F&F&F\end{array}$

That is the complete table for or.

Or is true if at least one of the disjuncts is true.
You can see only in the last line where both are false do we get false,
• Nov 25th 2009, 12:36 PM
novice
Thank you, Plato,
You did a good job explaining it with the phrase, "True if at least one is true."

Thanks again for your speedy delivery.