Section EqTheory.
Variables (aT : finType) (rT : eqType).
Notation fT := {ffun aT -> rT}.
Implicit Types (y : rT) (D : {pred aT}) (R : {pred rT}) (f : fT).

Lemma supportP y D g :
reflect (forall x, x \notin D -> g x = y) (y.-support g \subset D).