Re: negotiation by failure- list operations

In fact even with my original delete1 (ie without the extra cut), if
you press the return key in SWI prolog instead of ';' you will get the
yes:

2 ?- delete1(a,[b,c],X).

X = [b, c]

% At this point the top level waits for a response -
% pressing ';' means try again but [return] means "that's enough"

Yes
3 ?-

.