Re: strange behaviour

russell kym horsell wrote:

Right. Append has no clauses -- it's normally a builtin.

What do you mean by "normally' ?
It's not an ISO built-in.
It's not a built-in in SICStus, Yap, XSB, SWI-Prolog.


You'll have
to provide for builtins in your meta-interp or define an appropriate
append with clause(s:).

If it's a built-in in the Prolog system you are using (e.g. GNU-Prolog
and B-Prolog), you won't be able to define clauses for it.

Cheers

Bart Demoen
.