Goal:
    __x2 : Z  __x1 : Z
  ============================
   (let __wit := [] in
    let __varmap := VarMap.Branch (VarMap.Elt __x2) __x1 VarMap.Empty in
    let __ff :=
      Tauto.IMPL
        (Tauto.A Tauto.isProp
           {|
             RingMicromega.Flhs := EnvRing.PEX 2;
             RingMicromega.Fop := RingMicromega.OpLe;
             RingMicromega.Frhs := EnvRing.PEc 0
           |} tt) None
        (Tauto.A Tauto.isProp
           {|
             RingMicromega.Flhs :=
               EnvRing.PEadd (EnvRing.PEX 1) (EnvRing.PEX 2);
             RingMicromega.Fop := RingMicromega.OpLe;
             RingMicromega.Frhs := EnvRing.PEX 1
           |} tt) in
    __x2 <= 0 -> __x1 + __x2 <= __x1)


DEBUG:Going to execute:
let __wit := fresh "__wit" in
           let __varmap := fresh "__varmap" in
           let __ff := fresh "__ff" in
           intros __wit __varmap __ff; exact
            (ZMicromega.ZTautoChecker_sound __ff __wit
               (eq_refl <: ZMicromega.ZTautoChecker __ff __wit = true)
               (VarMap.find 0 __varmap))