End DisjointUnion.
Section EqType.
Variables (K : ordType) (V : eqType).
Definition feq (s1 s2 : finMap K V) := seq_of s1 == seq_of s2.

(* Specifications: *)
Lemma feqP : Equality.axiom feq.
Canonical Structure fmap_eqMixin := EqMixin feqP.