Goal:
    G : t  z : Z
  ============================
   (z <=? 0 -> exists z0 : Z, Some z = Some z0 /\ z0 <= 0)


DEBUG:Going to execute:
<Coq.Init.Tauto.with_uniform_flags>
            ltac:(fun flags => <Coq.Init.Tauto.intuition_gen> flags tac)