Prolog expert system problem

[slavano]

Hey all, 

 

I am trying to make a knowledge base for an expert system called Exshell using SWI-Prolog. I have tried posting on their forum but have got no response. when the expert system uses the fallowing

 

rule((A :- B),C1).

 

to call the fallowing in the knowledge base

 

rule((move(St1, Cu1) :- 
    (start(state(St1, St2, St3, St4)),
    switch(state(St1, St2, St3, St4), state(Cu1, Cu2, Cu3, Cu4), [state(St1, St2, St3, St4)]))), 100).


start(state(east_side, east_side, east_side, east_side)).


switch(state(F1, G1, W1, C1), state(F2, G2, W2, C2), History) :-
    is_end(state(F1, G1, W1, C1))
    ;
    move_state(state(F1, G1, W1, C1), state(F2, G2, W2, C2)),
    not(is_history(state(F2, G2, W2, C2), History)),
    switch(state(F2, G2, W2, C2), state(F3, G3, W3, C3), [state(F2, G2, W2, C2)|History]).

 

it returns the fallowing to.

 

A = move(_4238,_4240)

 

Is it not able to see the start predicate? if so, why not and how do I fix it?

 

Thanks in advance!

[elpiop]

[trace] 22 ?- rule((A:-B),C1).
   Call: (8) rule((_2174:-_2176), _2182) ? creep
   Exit: (8) rule((move(_2466, _2468):-start(state(_2466, _2484, _2486, _2488)), switch(state(_2466, _2484, _2486, _2488), state(_2468, _2512, _2514, _2516), [state(_2466, _2484, _2486, _2488)])), 100) ? creep

A = move(_2466, _2468),

B =  (start(state(_2466, _2484, _2486, _2488)), switch(state(_2466, _2484, _2486, _2488), state(_2468, _2512, _2514, _2516), [state(_2466, _2484, _2486, _2488)])),
C1 = 100.

You can view the trace to see what is being unified. Not sure what you're trying to accomplish here, though, so I can't give any further advice. Plus, I don't really remember Prolog too well.