proposition: Lemma oplusC (a b: T1): T1nf a -> T1nf b -> a o+ b = b o+ a.
proof: Proof. move => ? ?; by rewrite /oplus oplus_comm ?hnf_g2h. Qed.
imports: mathcomp(all_ssreflect zify) Coq(Logic.Eqdep_dec) hydras(DecPreOrder ON_Generic) hydras(T1 E0 Hessenberg) gaia_hydras(T1Bridge)