door(a,b).
door(b,e).
door(b,c).
door(d,e).
door(c,d).
door(e,f).
door(g,e).

go(Start,Dest,Route) :-
	go0(Start,Dest,[],Route).
	
go0(X,X,T,[X|T]).
go0(Place,Y,T,R) :-
	legalnode(Place,T,Next),
	go0(Next,Y,[Place|T],R).

legalnode(X,Trail,Y) :-
	(door(X,Y);door(Y,X)), legal(Y,Trail).

legal(X,[]).
legal(X,[H|T]) :- \+ X = H, legal(X,T).

hasphone(g).