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:- object(heuristic_search(_),
instantiates(class),
specializes(search_strategy)).
:- info([
version is 1.0,
author is 'Paulo Moura',
date is 1998/3/23,
comment is 'Heuristic state space search strategies.',
parnames is ['Threshold']]).
:- public(threshold/1).
:- mode(threshold(?number), one).
:- info(threshold/1,
[comment is 'Search cost threshold.',
argnames is ['Threshold']]).
:- public(solve/4).
:- mode(solve(+object, +nonvar, -list, -number), zero_or_more).
:- info(solve/4,
[comment is 'State space search solution.',
argnames is ['Space', 'State', 'Path', 'Cost']]).
:- protected(search/5).
:- mode(search(+object, +nonvar, +number, -list, -number), zero_or_more).
:- info(search/5,
[comment is 'State space search solution.',
argnames is ['Space', 'State', 'Threshold', 'Path', 'Cost']]).
solve(Space, State, Path) :-
::solve(Space, State, Path, _).
solve(Space, State, Path, Cost) :-
::threshold(Threshold),
::search(Space, State, Threshold, Path, Cost).
threshold(Threshold) :-
parameter(1, Threshold).
:- end_object.
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