Goal:
  
  x : string
  IHx : forall y : string,
        CompareSpec (x = y) (lt x y) (lt y x) (compare x y)
  b0 : Byte.byte
  y : string
  H : lt y x
  ============================
   (compare y x = Lt)


DEBUG:Going to execute:
(solve [ do_atom | use_hyps; do_ccl ]) ||
             fail "Cannot solve this goal"