Program
move(state(middle,onbox,middle,hasnot),
grasp,
state(middle,onbox,middle,has)).
move(state(P,onfloor,P,H),
climb,
state(P,onbox,P,H)).
move(state(P1,onfloor,P1,H),
drag(P1,P2),
state(P2,onfloor,P2,H)).
move(state(P1,onfloor,B,H),
walk(P1,P2),
state(P2,onfloor,B,H)).
canget(state(_,_,_,has)).
canget(State1) :-
move(State1,_,State2),
canget(State2).
Output
| ?- [monkey_banana].
compiling D:/TP Prolog/Sample_Codes/monkey_banana.pl for byte code...
D:/TP Prolog/Sample_Codes/monkey_banana.pl compiled, 17 lines read - 2167 bytes written, 19 ms
(31 ms) yes
| ?- canget(state(atdoor, onfloor, atwindow, hasnot)).
true ?
yes
| ?- trace
.
The debugger will first creep -- showing everything (trace)
yes
{trace}
| ?- canget(state(atdoor, onfloor, atwindow, hasnot)).
1 1 Call: canget(state(atdoor,onfloor,atwindow,hasnot)) ?
2 2 Call: move(state(atdoor,onfloor,atwindow,hasnot),_52,_92) ?
2 2 Exit:move(state(atdoor,onfloor,atwindow,hasnot),walk(atdoor,_80),state(_80,onfloor,atwindow,hasnot)) ?
3 2 Call: canget(state(_80,onfloor,atwindow,hasnot)) ?
4 3 Call: move(state(_80,onfloor,atwindow,hasnot),_110,_150) ?
4 3 Exit: move(state(atwindow,onfloor,atwindow,hasnot),climb,state(atwindow,onbox,atwindow,hasnot)) ?
5 3 Call: canget(state(atwindow,onbox,atwindow,hasnot)) ?
6 4 Call: move(state(atwindow,onbox,atwindow,hasnot),_165,_205) ?
6 4 Fail: move(state(atwindow,onbox,atwindow,hasnot),_165,_193) ?
5 3 Fail: canget(state(atwindow,onbox,atwindow,hasnot)) ?
4 3 Redo: move(state(atwindow,onfloor,atwindow,hasnot),climb,state(atwindow,onbox,atwindow,hasnot)) ?
4 3 Exit: move(state(atwindow,onfloor,atwindow,hasnot),drag(atwindow,_138),state(_138,onfloor,_138,hasnot)) ?
5 3 Call: canget(state(_138,onfloor,_138,hasnot)) ?
6 4 Call: move(state(_138,onfloor,_138,hasnot),_168,_208) ?
6 4 Exit: move(state(_138,onfloor,_138,hasnot),climb,state(_138,onbox,_138,hasnot)) ?
7 4 Call: canget(state(_138,onbox,_138,hasnot)) ?
8 5 Call: move(state(_138,onbox,_138,hasnot),_223,_263) ?
8 5 Exit: move(state(middle,onbox,middle,hasnot),grasp,state(middle,onbox,middle,has)) ?
9 5 Call: canget(state(middle,onbox,middle,has)) ?
9 5 Exit: canget(state(middle,onbox,middle,has)) ?
7 4 Exit: canget(state(middle,onbox,middle,hasnot)) ?
5 3 Exit: canget(state(middle,onfloor,middle,hasnot)) ?
3 2 Exit: canget(state(atwindow,onfloor,atwindow,hasnot)) ?
1 1 Exit: canget(state(atdoor,onfloor,atwindow,hasnot)) ?
true ?
(78 ms) yes
