Inductive dist_chain (A : Set) : prechain A -> Prop :=
  | dist_single : forall x : Map A, dist_chain A (single A x)
  | dist_concat_s :
      forall x y : Map A, x <> y -> dist_chain A (concat A (single A x) y)
  | dist_concat_m :
      forall (x y : Map A) (z : prechain A),
      x <> y ->
      dist_chain A (concat A z x) -> dist_chain A (concat A (concat A z x) y).Inductive dist_chain (A : Set) : prechain A -> Prop :=
  | dist_single : forall x : Map A, dist_chain A (single A x)
  | dist_concat_s :
      forall x y : Map A, x <> y -> dist_chain A (concat A (single A x) y)
  | dist_concat_m :
      forall (x y : Map A) (z : prechain A),
      x <> y ->
      dist_chain A (concat A z x) -> dist_chain A (concat A (concat A z x) y).Inductive dist_chain (A : Set) : prechain A -> Prop :=
  | dist_single : forall x : Map A, dist_chain A (single A x)
  | dist_concat_s :
      forall x y : Map A, x <> y -> dist_chain A (concat A (single A x) y)
  | dist_concat_m :
      forall (x y : Map A) (z : prechain A),
      x <> y ->
      dist_chain A (concat A z x) -> dist_chain A (concat A (concat A z x) y).Inductive dist_chain (A : Set) : prechain A -> Prop :=
  | dist_single : forall x : Map A, dist_chain A (single A x)
  | dist_concat_s :
      forall x y : Map A, x <> y -> dist_chain A (concat A (single A x) y)
  | dist_concat_m :
      forall (x y : Map A) (z : prechain A),
      x <> y ->
      dist_chain A (concat A z x) -> dist_chain A (concat A (concat A z x) y).Inductive non_dist_chain (A : Set) : prechain A -> Prop :=
  | non_dist_concat_s :
      forall x : Map A, non_dist_chain A (concat A (single A x) x)
  | non_dist_concat_m_hd :
      forall (x : Map A) (z : prechain A),
      non_dist_chain A (concat A (concat A z x) x)
  | non_dist_concat_m_tl :
      forall (x y : Map A) (z : prechain A),
      non_dist_chain A (concat A z x) ->
      non_dist_chain A (concat A (concat A z x) y).Inductive non_dist_chain (A : Set) : prechain A -> Prop :=
  | non_dist_concat_s :
      forall x : Map A, non_dist_chain A (concat A (single A x) x)
  | non_dist_concat_m_hd :
      forall (x : Map A) (z : prechain A),
      non_dist_chain A (concat A (concat A z x) x)
  | non_dist_concat_m_tl :
      forall (x y : Map A) (z : prechain A),
      non_dist_chain A (concat A z x) ->
      non_dist_chain A (concat A (concat A z x) y).Inductive non_dist_chain (A : Set) : prechain A -> Prop :=
  | non_dist_concat_s :
      forall x : Map A, non_dist_chain A (concat A (single A x) x)
  | non_dist_concat_m_hd :
      forall (x : Map A) (z : prechain A),
      non_dist_chain A (concat A (concat A z x) x)
  | non_dist_concat_m_tl :
      forall (x y : Map A) (z : prechain A),
      non_dist_chain A (concat A z x) ->
      non_dist_chain A (concat A (concat A z x) y).Inductive non_dist_chain (A : Set) : prechain A -> Prop :=
  | non_dist_concat_s :
      forall x : Map A, non_dist_chain A (concat A (single A x) x)
  | non_dist_concat_m_hd :
      forall (x : Map A) (z : prechain A),
      non_dist_chain A (concat A (concat A z x) x)
  | non_dist_concat_m_tl :
      forall (x y : Map A) (z : prechain A),
      non_dist_chain A (concat A z x) ->
      non_dist_chain A (concat A (concat A z x) y).Definition sas_chain (A : Set) (T : mEnsemble A) (r : mRelation A)
  (p : prechain A) : Prop := chain A T r p /\ dist_chain A p.Definition dist_compl_def_0 (A : Set) (p : prechain A) : Prop :=
  dist_chain A p \/ non_dist_chain A p.

(* Specifications: *)
Lemma dist_compl_0 : forall (A : Set) (m : Map A), dist_compl_def_0 A (single A m).