60 lines
918 B
Plaintext
60 lines
918 B
Plaintext
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:- object(water_jug,
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instantiates(state_space)).
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:- info([
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version is 1.0,
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authors is 'Paulo Moura',
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date is 1998/3/23,
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comment is 'Water jug state space search problem.']).
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initial_state(start, (0, 0)).
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goal_state(end1, (2, 0)).
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goal_state(end2, (0, 2)).
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next_state((X, Y), (4, Y)) :-
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X < 4.
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next_state((X, Y),(X, 3)) :-
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Y < 3.
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next_state((X, Y), (4, Z)) :-
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Y > 0, X < 4,
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Aux is X + Y, Aux >= 4,
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Z is Y - (4 - X).
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next_state((X, Y), (Z, 3)) :-
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X > 0, Y < 3,
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Aux is X + Y, Aux >= 4,
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Z is X - (3 - Y).
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next_state((X, Y),(Z, 0)) :-
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Y > 0,
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Aux is X + Y, Aux =< 4,
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Z is Y + X.
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next_state((X, Y),(0, Z)) :-
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X > 0,
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Aux is X + Y, Aux =< 3,
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Z is Y + X.
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next_state((X, Y), (0, Y)) :-
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X > 0.
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next_state((X, Y), (X, 0)) :-
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Y > 0.
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print_state((X, Y)) :-
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write('4-gallon jug: '), write(X), nl,
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write('3-gallon jug: '), write(Y), nl, nl.
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:- end_object.
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