>Fernando,
>
>this add up stuff instead of simplifying.
>
>

.F. # !.T.

>will end up the same as
>

?.F. = .T.

>
>as I wrote somewhere in this thread, it was only about teaching boolean algebra. Multiple negation and the like. Just like while
>

IF ll_X=.T.

>is superfuous.
>
>So I was just curious how old this one is and if it is known.

Oh, I get it now. Well, I think that almost nobody have found this bug because instintively ones write this:

? .F. # .T. or .F. = .T.

in regards of combining # and !

Seems like VFP didn't like using 2 or more operators together. I never tried it before.

Anyway, I've just looked at the help ("Relational Operators" topic), and there are listed all allowed ones, and this combinations are not allowed, then that's why the syntax error.

https://msdn.microsoft.com/en-US/library/3b6st626%28v=vs.80%29.aspx

Can't blame VFP, it's documented :)