Definition SRIDmorph : ring_morph 0 1 radd rmul SRsub SRopp req
                            0 1 radd rmul SRsub SRopp reqb (@IDphi R).

Lemma SRmorph_Rmorph : ring_morph rO rI radd rmul SRsub SRopp req cO cI cadd cmul cadd (fun x => x) ceqb phi.