% Naive approach

% states are simple atoms a, b, c, ... k.
% moves or successor states are directly hardwired into code

move(a,b).
move(a,c).
move(b,d).
move(b,e).
move(c,f).
move(c,g).
move(d,h).
move(e,i).
move(e,j).
move(f,k).

start(a).
goal(j).
goal(f).

% solve(State, Solution_Path)
% Start with  ?- solve(a, Sol).

solve(State, [State]) :-
    goal(State).

solve(State, [State|Sol]) :-
    move(State, NewState),
    solve(NewState, Sol).