bagof/3 issue

[flexoron]

v2.1.4

$ cat xyz.pl

isl({L},N) :- L = (_ is _+N).

testf :- findall(Z,(between(1,5,N),
                    (isl({X}, N), X = (Y is B+_), bagof(Y,X^B^(between(1,3,B),X),Z))
		   ),
	         M), write(M).

testb :- bagof(Z,N^X^Y^B^(between(1,5,N),
                          (isl({X}, N), X = (Y is B+_), bagof(Y,X^B^(between(1,3,B),X),Z))
	                 ),
	       M), write(M).

$ tpl xyz.pl
?- testf.
[[2,3,4],[3,4,5],[4,5,6],[5,6,7],[6,7,8]]   true.

?- testb.
[[2,3,4]]   true  % unexpected? expecting the whole list(see testf).
; [[3,4,5]] true
; [[4,5,6]] true
;  ... .
?-

testf: findall/3 works as expected and gathers up Z of (sub-)bagof/3, which works as expected, into M.

testb: bagof/3 does not collecting Z as findall/3 does but it should, shouldn't it?

[infradig]

It's the same with SWI Prolog. - ~/trealla (devel) $ swipl xyz.pl ?- testf. [[2,3,4],[3,4,5],[4,5,6],[5,6,7],[6,7,8]] true. ?- testb. [[2,3,4]] true ; [[3,4,5]] true ; [[4,5,6]] true ; [[5,6,7]] true ; [[6,7,8]] true.

…

On Thu, Aug 25, 2022 at 7:17 AM flexoron ***@***.***> wrote: v2.1.4 $ cat xyz.pl isl({L},N) :- L = (_ is _+N). testf :- findall(Z,(between(1,5,N), (isl({X}, N), X = (Y is B+_), bagof(Y,X^B^(between(1,3,B),X),Z)) ), M), write(M). testb :- bagof(Z,N^X^Y^B^(between(1,5,N), (isl({X}, N), X = (Y is B+_), bagof(Y,X^B^(between(1,3,B),X),Z)) ), M), write(M). $ tpl xyz.pl ?- testf. [[2,3,4],[3,4,5],[4,5,6],[5,6,7],[6,7,8]] true. ?- testb. [[2,3,4]] true ; [[3,4,5]] true ; [[4,5,6]] true ; ... . ?- testf: findall/3 works as expected and gathers up Z of sub-bagof/3, which works as expected, into M. testb: bagof/3 does not collecting Z as findall/3 does but it should, shouldn't it? — Reply to this email directly, view it on GitHub <#28>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AFNKSEXUYTDITRRNM6QIMQTV22GOLANCNFSM57QZSYKQ> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[infradig]

The problem is the anonymous variable, replace it with W like this... testb :- bagof(Z,N^X^Y^W^B^(between(1,5,N), (isl({X}, N), X = (Y is B+W), bagof(Y,X^B^(between(1,3,B),X),Z)) ), M), write(M).

…

On Thu, Aug 25, 2022 at 7:17 AM flexoron ***@***.***> wrote: v2.1.4 $ cat xyz.pl isl({L},N) :- L = (_ is _+N). testf :- findall(Z,(between(1,5,N), (isl({X}, N), X = (Y is B+_), bagof(Y,X^B^(between(1,3,B),X),Z)) ), M), write(M). testb :- bagof(Z,N^X^Y^B^(between(1,5,N), (isl({X}, N), X = (Y is B+_), bagof(Y,X^B^(between(1,3,B),X),Z)) ), M), write(M). $ tpl xyz.pl ?- testf. [[2,3,4],[3,4,5],[4,5,6],[5,6,7],[6,7,8]] true. ?- testb. [[2,3,4]] true ; [[3,4,5]] true ; [[4,5,6]] true ; ... . ?- testf: findall/3 works as expected and gathers up Z of sub-bagof/3, which works as expected, into M. testb: bagof/3 does not collecting Z as findall/3 does but it should, shouldn't it? — Reply to this email directly, view it on GitHub <#28>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AFNKSEXUYTDITRRNM6QIMQTV22GOLANCNFSM57QZSYKQ> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[flexoron]

True! N^X^W^ is good enough, Y^B^ not needed. Thanks a lot!

testb :- bagof(Z,N^X^W^(between(1,5,N),
isl({X}, N), X = (Y is B+W), bagof(Y,X^B^(between(1,3,B),X),Z)
),
M), write(M).