Goal:
    z : Z  z0 : Z  z1 : Z  H : (z <= z1)%Z  H0 : (z0 <= z1)%Z
  ============================
   (Z.max z z0 <= z1)%Z


DEBUG:Going to execute:
fun tauto_flags X1 => <coq-core.plugins.tauto::is_unit_or_eq@0>