`{Naturals N} `{IsSemiCRing SR} (f g: N -> SR) `{!IsSemiRingPreserving f} `{!IsSemiRingPreserving g} x : f x = g x. Proof. rewrite (to_semiring_unique f), (to_semiring_unique g);reflexivity. Qed.
Require Import Require Import Import SemiRings.