Date: Nov 20, 2012 4:21 AM
Author: Graham Cooper
Subject: Re: PROLOG does SO have NOT() !!

> A predicate with more than 2 values!
>
> gender(m).            1
> gender(f).                2
> not(gender(X)).         3
>
> Prolog searches for a match from top to bottom,
> it will return
> --> gender(m)
>
> or
> --> not(gender(t)).
>
> for any value other than m or f!
>


Correction...  it will match X to 'm' or 'f' if you search for
not(gender(m))

You have to specify the final option(s).

gender(m).
gender(f).
not(gender(t)).
not(gender(o)).

Herc