Goal:
    s : t  s' : t  e : false = true  H : lt s s'
  ============================
   (s = s')


DEBUG:Going to execute:
match goal with
           | H:_ /\ _ |- _ => exact H || (destruct_hyp H; use_hyps)
           | H:_ |- _ => solve [ inversion H ]
           | _ => idtac
           end