set(production).

formulas(usable).
  J(x,y) & y < 4 -> J(x,y+1)   #answer("up").                       
  J(x,y) & x < 4 -> J(x+1,y)   #answer("right").
end_of_list.

formulas(assumptions).
  J(0,0)                        #answer("Init state: J(0,0)"). 
end_of_list.

formulas(goals).
  J(3,4).
end_of_list.
