>Example:
>

>* this is simple and clear
>IF doOperation1()
>  IF  doOperation2() && executed for doOperation1() = .T.
>      doOperation3() && executed for doOperation1() AND doOperation2() = .T.
>  ENDIF
>ENDIF
>* a developer can use this, but this is not equal to the previous code
>= doOperation1() ;
> .AND. doOperation2() ; && executed for doOperation1() = .T. or .NULL.
>    .AND. doOperation3() && executed for (doOperation1() = .T. or .NULL.) AND (doOperation2() = .T. or .NULL.)
>

>
>Fabio

Interesting; I thought the two versions would work the same; but I had not thought about NULL.

I hadn't experimented, and didn't know that NULL AND .F. = .F. I would have expected NULL, but I think that .F. actually makes more sense.