custom_explicit_sets.pl

add_id_pairs([],_,R,R).

add_id_pairs([Key|T],LastX,AVL,Res) :-
    (Key = (X,Y) -> true ; add_error_and_fail(add_id_pairs,'Not a relation element: ',Key)),
    (X=Y -> AVL2=AVL /* must already be in closure1 result */
    ; (LastX==X -> AVL1=AVL ; avl_store((X,X),AVL,true,AVL1)), % already added
    avl_store((Y,Y),AVL1,true,AVL2)
    ),
    add_id_pairs(T,X,AVL2,Res).

closure0_for_explicit_set(avl_set(A),Res) :-
    avl_domain(A,List),
    closure1_for_explicit_set(avl_set(A),Res1),
    (Res1==[] -> A2=empty ; Res1 = avl_set(A2)),
    add_id_pairs(List,none,A2,A3),
    construct_avl_set(A3,S3),
    kernel_objects:equal_object(Res,S3,closure0_for_explicit_set).

in_closure0_membership_test_wf((A,B),CSRelation,MemRes,WF) :-
    equality_objects_wf(A,B,MemRes1,WF),
    (MemRes1==pred_true -> MemRes=pred_true
    ; in_closure1_membership_test_wf((A,B),CSRelation,MemRes2,WF),
    b_interpreter_check:disjoin(MemRes1,MemRes2,MemRes,priority(1),priority(1000),WF)
).

relational_reflexive_closure(Relation,Result) :-
    try_expand_and_convert_to_avl_with_check(Relation,ARelation,relational_reflexive_closure),
    relational_reflexive_closure2(ARelation,Result).

relational_reflexive_closure2(ARelation,Result) :- % print_term_summary(closure(ARelation,Result)),
    (closure0_for_explicit_set(ARelation,Res)
    -> kernel_objects:equal_object(Res,Result)
    ; (expand_custom_set_to_list(ARelation,ERelation,_,relational_reflexive_closure2),
    is_full_relation(ERelation,WaitVar),
    compute_trans_closure(ERelation,Result1,WaitVar),
    % print(adding_id(ERelation,Result1)),nl,
    rel_iterate0(ERelation,Result1,Result)
%, print(done(Result)),nl
)
).

union_of_avl(A1,A2,ARes) :- MaxDiff=4,
    avl_tools:avl_height_compare_up_to(A1,A2,MaxDiff,SmHeight,Res),
    (SmHeight =< 2 -> union_of_avl2(A1,A2,ARes)
    ; Res =eq -> union_of_avl2(A1,A2,ARes)
    ; Res=lt -> union_of_avl1(A2,A1,ARes)
    ; union_of_avl1(A1,A2,ARes)).

union_of_avl1(A1,A2,ARes) :- %Sz2>2, Sz1 =< Sz2+3, % difference not too big; Sz2 at least a certain size
    %!,
    print(union(Sz1,Sz2)),nl,
    avl_to_list(A2,List2), % get all members
    avl_to_list(A1,List1),
    ord_union(List1,List2,L12),
    ord_list_to_avl(L12,ARes).

union_of_avl2(A1,A2,ARes) :- % this version is better when A2 is small compared to A1
    avl_domain(A2,List2), % get all members
    add_to_avl(List2,A1,ARes).