> > ...
> > I'm not familiar with Poplog's implementation of Prolog, but in a
> > typical Prolog system, the following two lines should work.
> > ....
> > :- op( 1100, xfy, | ) .
> >
> > X | Y :- X ; Y .
>
> Thanks Alan.
> The required precedence in poplog prolog is 254.
>
> Unfortunately the compiler complains if it finds "|" in either of
> those two positions.
>
Just check whether your prolog compiler can accept
the "op" command if you put single quotes around the '|'.
This should turn it into an atom,
which may make the "op" command work.
:- op( 1100, xfy, '|' ) .
X | Y :- X ; Y .
--
Martin Sondergaard,
London.
|