🚀 go-pugleaf

/* Written  2:57 pm  Feb  7, 1989 by rar@DEIMOS.ADS.COM in clio:comp.lang.prolog */
/* ---------- "existential quantification in bagof" ---------- */
=>   E.g., given the DB
=>
=>   foo(1,2,3,4).
=>   foo(2,3,4,5).
=>   foo(3,4,5,6).
=>   foo(4,5,6,7).
=>
=>   I can do
=>
=>   | ?- T = p(X,Y,Z), setof(First, T^foo(First,X,Y,Z), Set).
=>
=>   T = p(X,Y,Z),
=>   X = _79,
=>   Y = _94,
=>   Z = _109,
=>   First = _132,
=>   Set = [1,2,3,4] 
=>
=>   I'd be curious to find out if other Prologs work like this.

This is how it works in TI-Prolog. But how about 'findall'? I think this 
is the peculiar case. See my response to the original existential
quantification question.
                                        -- Dale Gerdemann
                                           U of Ill
                                           Dept of Linguistics