Expert system help

[Travis LaVallee]

Hey all, 

I am trying to make a knowledge base for an expert system called Exshell. when the expert system uses the fallowing

rule((A :- B),C1).

to call

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?

Thanks in advance!