fact: Fixpoint g2h (alpha : T2) : hT2 := match alpha with zero => hzero | cons a b n c => hcons (g2h a)(g2h b) n (g2h c) end.
imports: mathcomp(all_ssreflect zify) Coq(Logic.Eqdep_dec) hydras(DecPreOrder ON_Generic T2 Gamma0)