use append/3 rather than set_difference/3 to gather witnesses in bagof/3 and setof/3
@@ -745,11 +745,10 @@ findall_with_existential(Template, Goal, PairedSolutions, Witnesses0, Witnesses)
bagof(Template, Goal, Solution) :-
error:can_be(list, Solution),
- term_variables(Template, TemplateVars0),
- term_variables(Goal, GoalVars0),
- sort(TemplateVars0, TemplateVars),
- sort(GoalVars0, GoalVars),
- set_difference(GoalVars, TemplateVars, Witnesses0),
+ term_variables(Template, TemplateVars),
+ term_variables(Goal, GoalVars),
+ term_variables(TemplateVars+GoalVars, TGVs),
+ lists:append(TemplateVars, Witnesses0, TGVs),
findall_with_existential(Template, Goal, PairedSolutions0, Witnesses0, Witnesses),
keysort(PairedSolutions0, PairedSolutions),
group_by_variants(PairedSolutions, GroupedSolutions),
@@ -773,11 +772,10 @@ iterate_variants_and_sort([_|GroupSolutions], Ws, Solution) :-
setof(Template, Goal, Solution) :-
error:can_be(list, Solution),
- term_variables(Template, TemplateVars0),
- term_variables(Goal, GoalVars0),
- sort(TemplateVars0, TemplateVars),
- sort(GoalVars0, GoalVars),
- set_difference(GoalVars, TemplateVars, Witnesses0),
+ term_variables(Template, TemplateVars),
+ term_variables(Goal, GoalVars),
+ term_variables(TemplateVars+GoalVars, TGVs),
+ lists:append(TemplateVars, Witnesses0, TGVs),
findall_with_existential(Template, Goal, PairedSolutions0, Witnesses0, Witnesses),
keysort(PairedSolutions0, PairedSolutions),
group_by_variants(PairedSolutions, GroupedSolutions),
