Goal:
    x : Z  z : Z  H : False  H0 : True
  ============================
   (x <= z)%Z


DEBUG:Going to execute:
elim H
Level 3: evaluation returns
<coq-core.plugins.tauto::is_empty@0>
where
tauto_flags := 
of type
tauto_flags
X1 := False
of type
constr of type tacvalue