Definition Rcompare x y :=
  match total_order_T x y with
  | inleft (left _) => Lt
  | inleft (right _) => Eq
  | inright _ => Gt
  end.Inductive Rcompare_prop (x y : R) : comparison -> Prop :=
  | Rcompare_Lt_ : (x < y)%R -> Rcompare_prop x y Lt
  | Rcompare_Eq_ : x = y -> Rcompare_prop x y Eq
  | Rcompare_Gt_ : (y < x)%R -> Rcompare_prop x y Gt.Inductive Rcompare_prop (x y : R) : comparison -> Prop :=
  | Rcompare_Lt_ : (x < y)%R -> Rcompare_prop x y Lt
  | Rcompare_Eq_ : x = y -> Rcompare_prop x y Eq
  | Rcompare_Gt_ : (y < x)%R -> Rcompare_prop x y Gt.Inductive Rcompare_prop (x y : R) : comparison -> Prop :=
  | Rcompare_Lt_ : (x < y)%R -> Rcompare_prop x y Lt
  | Rcompare_Eq_ : x = y -> Rcompare_prop x y Eq
  | Rcompare_Gt_ : (y < x)%R -> Rcompare_prop x y Gt.Inductive Rcompare_prop (x y : R) : comparison -> Prop :=
  | Rcompare_Lt_ : (x < y)%R -> Rcompare_prop x y Lt
  | Rcompare_Eq_ : x = y -> Rcompare_prop x y Eq
  | Rcompare_Gt_ : (y < x)%R -> Rcompare_prop x y Gt.

Theorem Rcompare_not_Lt : forall x y, (y <= x)%R -> Rcompare x y <> Lt.