proposition: Lemma remf1_set f (k k' : K) (v : V) : f.[k' <- v].[~ k] = if k == k' then f.[~ k] else f.[~ k].[k' <- v].
proof: Proof. by rewrite remf_set inE eq_sym. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrnat eqtype ssrfun seq) mathcomp(choice path finset finfun fintype bigop)