Pereira%SRI-AI@sri-unix.UUCP (10/17/83)
In my latest "findall vs. bagof" example, I got my 'a's and 'b's mixed up. The reply to the query is S = [1,3] with bagof, and S = [1,2,3] or S = [1,3] with findall depending on the order of goals. Sorry for the confusion. Thanks to Paul Broome for pointing this out. With respect to the discussion of "is_all in pure Prolog", it is clear that the general "is_all" with complex goals is rather tricky to implement because all the abstracted variables need to be replaced by fresh variables each time round the recursion. I'm still confused by this discussion, however. What is wrong with setof/bagof ? Also, what is the relevance of abstract datatypes to this problem ? -- Fernando Pereira