Re: So what's null then if it's not nothing?

paul c wrote:
> Jon Heggland wrote:
>
> > ...
> > No. He doesn't define equivalence; AND, OR and NOT is not sufficient. He
> > could very well have envisioned an equivalence truth table where w<->w
> > is w, not T.
> > ...
>
> Just interloping here, so I don't really know the thrust of the
> conversation, but the above caught my eye. If w<->w is meant as 'w if
> and only if w', surely <AND> is equivalent?

In the classical propositional logic and in Lukasiewicz's 3VL '<->' evaluates to 'true' when both operands have the same truth value and to 'false' otherwise. 'if and only if' is just another name for '<->'.

>
> p
Received on Mon Dec 05 2005 - 12:41:28 CST