287 lines
4.6 KiB
Prolog
287 lines
4.6 KiB
Prolog
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:- module(meld_interpreter,
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[
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live/0,
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delete/1,
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push/1,
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first/2,
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min/3,
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max/3,
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minval/3,
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maxval/3
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]).
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:- use_module(meldp,
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[
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run/1
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]).
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:- use_module(library(nb),
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[
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nb_queue/1,
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nb_queue_enqueue/2,
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nb_queue_dequeue/2
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]).
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:- initialization
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init_meld_queue.
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:- dynamic speculative_delete/3.
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live :-
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repeat,
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( pop(Goal) ->
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format('-~w~n',[Goal]),
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run(Goal),
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fail
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;
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!,
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done
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).
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done :-
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speculative_delete(_, _, _), !,
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push_residuals,
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live.
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done :-
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current_predicate(meld_program:P),
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P \= run/1,
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% P \= neighbor/2,
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% P \= root/1,
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listing(meld_program:P),
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fail.
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done.
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delete(Fact) :-
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nb_getval(meld_queue, Queue),
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retract(meld_program:Fact),
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nb_queue_enqueue(Queue, deleted(Fact)),
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live.
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pop(Goal) :-
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nb_getval(meld_queue, Queue),
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nb_queue_dequeue(Queue, Goal).
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push(Goal) :-
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clause(meld_program:Goal,_,Ref),
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!,
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increase_reference_count(Ref),
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fail.
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push(Goal) :-
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format('+~w~n',[Goal]),
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nb_getval(meld_queue, Queue), !,
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assert(meld_program:Goal),
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nb_queue_enqueue(Queue, Goal).
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% create a queue
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init_meld_queue :-
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nb_queue(Queue),
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nb_setval(meld_queue, Queue).
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first(Skel,Goal) :-
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meld_program:Skel, !,
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cache(Goal).
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first(_,Goal) :-
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cache(Goal),
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push(Goal).
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max(Skel,Arg,Goal) :-
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meld_program:Skel,
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arg(Arg, Skel, A0),
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arg(Arg, Goal, AN),
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AN =< A0, !,
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cache(Goal).
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max(Skel,_,Goal) :-
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clean(Skel),
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cache(Goal),
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push(Goal).
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min(Skel,Arg,Goal) :-
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meld_program:Skel,
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arg(Arg, Skel, A0),
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arg(Arg, Goal, AN),
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AN >= A0, !,
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cache(Goal).
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min(Skel,_,Goal) :-
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clean(Skel),
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cache(Goal),
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push(Goal).
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clean(Skel) :-
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% format('D~w~n',[Skel]),
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retractall(meld_program:Skel).
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cache(Goal) :-
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clause(meld_cache:Goal,_,Ref),
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!,
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increase_reference_count(Ref).
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cache(Goal) :-
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assert(meld_cache:Goal).
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deleted(Goal) :-
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clause(meld_program:Goal,_,Ref),
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decrease_reference_count(Ref),
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!,
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force_delete(Goal, Ref),
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complete_delete(Goal).
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deleted(Goal) :-
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retract(speculative_delete(Goal, Ref, Count)), !,
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NCount is Count-1,
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(
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NCount > 0
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->
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assert(speculative_delete(Goal, Ref, Count))
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;
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true
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).
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deleted(Goal) :-
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% format('-~w~n',[Goal]),
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complete_delete(Goal).
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complete_delete(Goal) :-
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nb_getval(meld_queue, Queue), !,
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retract(meld_program:Goal),
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nb_queue_enqueue(Queue, deleted(Goal)).
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force_delete(Goal, Ref) :-
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current_reference_count(Ref, Count),
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assert(speculative_delete(Goal, Ref, Count)).
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push_residuals :-
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retract(speculative_delete(Goal, _, _)),
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push(Goal),
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fail.
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push_residuals.
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%
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% first, cleanup cache
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%
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delete_from_first(_,Goal) :-
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clause(meld_program:Goal,_,Ref), !,
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(
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decrease_reference_count(Ref)
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->
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true
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;
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force_delete(Goal, Ref)
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),
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erase(Ref),
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retract(meld_cache:Goal),
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retract(meld_program:Goal),
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push(deleted(Goal)),
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once(meld_cache:VGoal),
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push(VGoal).
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delete_from_first(Goal) :-
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retract(speculative_delete(Goal, Ref, Count)), !,
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NCount is Count-1,
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(
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NCount > 0
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->
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assert(speculative_delete(Goal, Ref, Count))
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;
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true
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).
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delete_from_first(Goal) :-
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retract(meld_cache:Goal),
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push(deleted(Goal)).
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delete_from_max(VGoal,Arg,Goal) :-
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clause(meld_program:Goal,_,Ref), !,
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(
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decrease_reference_count(Ref)
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->
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true
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;
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force_delete(Goal, Ref)
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),
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erase(Ref),
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retract(meld_cache:Goal),
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push(deleted(Goal)),
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new_max(VGoal, Arg).
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delete_from_max(Goal) :-
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retract(speculative_delete(Goal, Ref, Count)), !,
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NCount is Count-1,
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(
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NCount > 0
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->
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assert(speculative_delete(Goal, Ref, Count))
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;
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true
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).
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delete_from_max(Goal) :-
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retract(meld_cache:Goal),
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push(deleted(Goal)).
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new_max(VGoal,Arg) :-
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arg(Arg, VGoal, A),
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maxval(A, meld_cache:VGoal, VGoal),
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push(VGoal).
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delete_from_min(VGoal,Arg,Goal) :-
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clause(meld_program:Goal,_,Ref), !,
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(
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decrease_reference_count(Ref)
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->
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true
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;
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force_delete(Goal, Ref)
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),
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erase(Ref),
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retract(meld_cache:Goal),
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push(deleted(Goal)),
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new_min(VGoal, Arg).
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delete_from_min(Goal) :- !,
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retract(speculative_delete(Goal, Ref, Count)),
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NCount is Count-1,
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(
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NCount > 0
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->
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assert(speculative_delete(Goal, Ref, Count))
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;
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true
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).
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delete_from_min(Goal) :-
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retract(meld_cache:Goal),
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push(deleted(Goal)).
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new_min(VGoal,Arg) :-
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arg(Arg, VGoal, A),
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minval(A, meld_cache:VGoal, VGoal),
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push(VGoal).
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:- meta_predicate minval(+,:,-), maxval(+,:,-).
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maxval(V,G,GMax) :-
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Memory = f(-inf,[]),
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(
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call(G),
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arg(1, Memory, V0),
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V > V0,
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nb_setarg(1, Memory, V),
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nb_setarg(2, Memory, V.GMax),
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fail
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;
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arg(2, Memory, V.GMax)
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).
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minval(V,G,GMin) :-
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Memory = f(+inf,[]),
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(
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call(G),
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arg(1, Memory, V0),
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V < V0,
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nb_setarg(1, Memory, V),
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nb_setarg(2, Memory, V.GMin),
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fail
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;
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arg(2, Memory, V.GMin)
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).
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