Section PolynomialTheory.
Variable R : ringType.
Implicit Types (a b c x y z : R) (p q r d : {poly R}).
Canonical poly_subType := Eval hnf in [subType of {poly R}].
Canonical poly_eqType := Eval hnf in [eqType of {poly R}].
Canonical poly_choiceType := Eval hnf in [choiceType of {poly R}].
Definition lead_coef p := p`_(size p).-1.

Lemma lead_coefE p : lead_coef p = p`_(size p).-1. Proof. by []. Qed.