Goal:
  
  __x4 : Z
  __x3 : Z
  __x2 : Z
  __x1 : Z
  __wit := [] : list ZMicromega.ZArithProof
  __varmap := VarMap.Branch
                (VarMap.Branch (VarMap.Elt __x4) __x2 VarMap.Empty) __x1
                (VarMap.Elt __x3) : VarMap.t Z
  __ff := Tauto.IMPL
            (Tauto.A Tauto.isProp
               {|
                 RingMicromega.Flhs := EnvRing.PEX 3;
                 RingMicromega.Fop := RingMicromega.OpLe;
                 RingMicromega.Frhs :=
                   EnvRing.PEadd (EnvRing.PEc 0)
                     (EnvRing.PEsub (EnvRing.PEX 4) (EnvRing.PEX 1))
               |} tt) None
            (Tauto.A Tauto.isProp
               {|
                 RingMicromega.Flhs :=
                   EnvRing.PEadd
                     (EnvRing.PEsub (EnvRing.PEX 1) (EnvRing.PEX 2))
                     (EnvRing.PEX 3);
                 RingMicromega.Fop := RingMicromega.OpLe;
                 RingMicromega.Frhs :=
                   EnvRing.PEsub (EnvRing.PEX 4) (EnvRing.PEX 2)
               |} tt) : Tauto.BFormula (RingMicromega.Formula Z) Tauto.isProp
  ============================
   (__x3 <= 0 + (__x4 - __x1) -> __x1 - __x2 + __x3 <= __x4 - __x2)


DEBUG:Going to execute:
exact
(ZMicromega.ZTautoChecker_sound __ff __wit
   (eq_refl <: ZMicromega.ZTautoChecker __ff __wit = true)
   (VarMap.find 0 __varmap))