Module DoNotation.
Notation "'do!' X <- A ; B" :=
(bindGen A (fun X => B))
(at level 200, X ident, A at level 100, B at level 200).
End DoNotation.
Definition ltColor (c1 c2: color) : Prop :=
match c1, c2 with
| Red, Black => True
| _, _ => False
end.

Lemma well_foulded_ltColor : well_founded ltColor.