Remark lem_redln_cons :
 forall (aP R Q : list (poly A0 eqA ltM)) (a b : poly A0 eqA ltM),
 In a aP ->
 In b aP ->
 redIn a b aP Q R ->
 forall (c : poly A0 eqA ltM) (Q1 : list (poly A0 eqA ltM)),
 Q = c :: Q1 ->
 red A A0 A1 eqA invA minusA multA divA eqA_dec n ltM ltM_dec c R ->
 redIn a b aP Q1 R.

Theorem redln_cons : forall (aP R Q : list (poly A0 eqA ltM)) (a b c : poly A0 eqA ltM), In a aP -> In b aP -> redIn a b aP (c :: Q) R -> red A A0 A1 eqA invA minusA multA divA eqA_dec n ltM ltM_dec c R -> redIn a b aP Q R.