database
    rstate(integer,integer)
predicates
    state(integer,integer)
    
clauses
        
    state(2,_).
    state(0,0):-
        not(rstate(0,0)),
        assert(rstate(0,0)),    
        state(0,0).
        
    state(X,Y):-
    
        X < 4,
        not(rstate(4,Y)),
        assert(rstate(4,Y)),
        write("\n Rule 1 => (4,",Y,")"),
        state(4,Y).
        
    state(X,Y):-
    
        Y < 3,
        not(rstate(X,3)),
        assert(rstate(X,3)),
        write("\n Rule 2 => (",X,",3)"),
        state(X,3).
    
    state(X,Y):-
    
        X>0,
        not(rstate(0,Y)),
        assert(rstate(0,Y)),
        write("\n Rule 5 => (0,",Y,")"),
        state(0,Y).
    
    state(X,Y):-
    
        Y>0,
        not(rstate(X,0)),
        assert(rstate(X,0)),
        write("\n Rule 6 => (",X,",0)"),
        state(X,0).
    
    state(X,Y):-
    
        X+Y >= 4,
        Y > 0,
        Z=Y-(4-X),
        not(rstate(4,Z)),
        assert(rstate(4,Z)),
        write("\n Rule 7 => (4,",Z,")"),
        state(4,Z).
    
    state(X,Y):-
    
        X+Y >= 3,
        X>0,
        Z=X-(3-Y),
        not(rstate(Z,3)),
        assert(rstate(Z,3)),
        write("\n Rule 8 => (",Z,",3)"),
        state(Z,3).
    
    state(X,Y):-
    
        X+Y <= 4,
        Y > 0,
        Z=X+Y,
        not(rstate(Z,0)),
        assert(rstate(Z,0)),
        write("\n Rule 9 => (",Z,",0)"),
        state(Z,0).
        
    state(X,Y):-
    
        X+Y <= 3,
        X>0,
        Z=X+Y,
        not(rstate(0,Z)),
        assert(rstate(0,Z)),
        write("\n Rule 10 => (0,",Z,")"),
        state(0,Z).
        
    state(X,Y):-
    
        X=0,
        Y=2,
        not(rstate(2,0)),
        assert(rstate(2,0)),
        write("\n Rule 11 => (2,0)"),
        state(2,0).
    
    state(X,Y):-
    
        X=2,
        assert(rstate(0,Y)),
        write("\n Rule 12 => (0,",Y,")"),
        state(0,Y).

goal
    makewindow(1,2,3,"Water Jug Problem",0,0,25,80),
    write("Initially state(0,0)"),
    state(0,0),
    save("output.txt").
    
OUTPUT

Initially state(0,0)
 Rule 1 => (4,0)
 Rule 2 => (4,3)
 Rule 5 => (0,3)
 Rule 9 => (3,0)
 Rule 2 => (3,3)
 Rule 7 => (4,2)
 Rule 5 => (0,2)
 Rule 9 => (2,0)
Press the SPACE bar

    output.txt

rstate(0,0)
rstate(4,0)
rstate(4,3)
rstate(0,3)
rstate(3,0)
rstate(3,3)
rstate(4,2)
rstate(0,2)
rstate(2,0)