Inductive successor_ordinal : Ordinal->Prop :=
  | intro_succ_ord: forall alpha:Ordinal,
    successor_ordinal (ordS alpha)
  | succ_ord_wd: forall alpha beta:Ordinal,
    successor_ordinal alpha -> alpha == beta ->
    successor_ordinal beta.Inductive successor_ordinal : Ordinal->Prop :=
  | intro_succ_ord: forall alpha:Ordinal,
    successor_ordinal (ordS alpha)
  | succ_ord_wd: forall alpha beta:Ordinal,
    successor_ordinal alpha -> alpha == beta ->
    successor_ordinal beta.Inductive successor_ordinal : Ordinal->Prop :=
  | intro_succ_ord: forall alpha:Ordinal,
    successor_ordinal (ordS alpha)
  | succ_ord_wd: forall alpha beta:Ordinal,
    successor_ordinal alpha -> alpha == beta ->
    successor_ordinal beta.Inductive limit_ordinal : Ordinal->Prop :=
  | intro_limit_ord: forall {I:Type} (alpha:I->Ordinal),
    (forall i:I, exists j:I, alpha i < alpha j) ->
    limit_ordinal (ord_sup alpha)
  | limit_ord_wd: forall alpha beta:Ordinal,
    limit_ordinal alpha -> alpha == beta ->
    limit_ordinal beta.Inductive limit_ordinal : Ordinal->Prop :=
  | intro_limit_ord: forall {I:Type} (alpha:I->Ordinal),
    (forall i:I, exists j:I, alpha i < alpha j) ->
    limit_ordinal (ord_sup alpha)
  | limit_ord_wd: forall alpha beta:Ordinal,
    limit_ordinal alpha -> alpha == beta ->
    limit_ordinal beta.Inductive limit_ordinal : Ordinal->Prop :=
  | intro_limit_ord: forall {I:Type} (alpha:I->Ordinal),
    (forall i:I, exists j:I, alpha i < alpha j) ->
    limit_ordinal (ord_sup alpha)
  | limit_ord_wd: forall alpha beta:Ordinal,
    limit_ordinal alpha -> alpha == beta ->
    limit_ordinal beta.

Lemma successor_ordinal_not_limit: forall alpha:Ordinal, successor_ordinal alpha -> ~ limit_ordinal alpha.