我正在與圖書館HOL/Library/Polynomial.thy
合作。Isabelle:多項式次數乘以常數
一個簡單的屬性不起作用。例如,中2x *2
度等於2x
程度 -
我如何證明引理(即去掉 「對不起」):
lemma mylemma:
fixes y :: "('a::comm_ring_1 poly)" and x :: "('a::comm_ring_1)"
shows "1 = 1" (* dummy *)
proof-
have "⋀ x. degree [: x :] = 0" by simp
from this have "⋀ x y. degree (y * [: x :]) = degree y" sorry
(* different notation: *)
from this have "⋀ x y. degree (y * (CONST pCons x 0)) = degree y" sorry
。
從Manuel的答案,解決我一直在尋找:
have 1: "⋀ x. degree [: x :] = 0" by simp
{
fix y :: "('a::comm_ring_1 poly)" and x :: "('a::comm_ring_1)"
from 1 have "degree (y * [: x :]) ≤ degree y"
by (metis Nat.add_0_right degree_mult_le)
}
感謝您的超級回答。事實上,「<= y度」對我的證明來說已經足夠了。 – mrsteve
在這種情況下,我sugest degree_mult_le,它甚至在交換半環上工作。 –