unwrapNewTyConEtad_maybe :: TyCon -> Maybe ([TyVar], Type, CoAxiom Unbranched)
unwrapNewTyConEtad_maybe (AlgTyCon { algTcRhs = NewTyCon { nt_co = co,
                                                           nt_etad_rhs = (tvs,rhs) }})
                           = Just (tvs, rhs, co)
unwrapNewTyConEtad_maybe :: TyCon -> Maybe ([TyVar], Type, CoAxiom Unbranched)
unwrapNewTyConEtad_maybe (AlgTyCon { algTcRhs = NewTyCon { nt_co = co,
                                                           nt_etad_rhs = (tvs,rhs) }})
                           = Just (tvs, rhs, co)
unwrapNewTyConEtad_maybe (AlgTyCon { algTcRhs = NewTyCon { nt_co = co,
                                                           nt_etad_rhs = (tvs,rhs) }})
                           = Just (tvs, rhs, co)