proposition: Lemma size_fgraph T1 T2 (r1 : {ffun I -> T1}) (r2 : {ffun I -> T2}) : size (fgraph r1) = size (fgraph r2).
proof: Proof. by rewrite !fgraph_codom /= !codomE !size_map. Qed.
imports: Coq(ssreflect ssrbool ssrfun Eqdep) mathcomp(ssrnat eqtype seq path) pcm(options axioms finmap) pcm(pcm unionmap) mathcomp(fintype tuple finfun)