let R be non degenerated Ring; for n being Ordinal
for p being Polynomial of n,R holds Lt (LM p) = Lt p
let n be Ordinal; for p being Polynomial of n,R holds Lt (LM p) = Lt p
let p be Polynomial of n,R; Lt (LM p) = Lt p
H:
Lt p is Element of Bags n
by PRE_POLY:def 12;
field (BagOrder n) = Bags n
by ORDERS_1:12;
then I:
BagOrder n linearly_orders Support (LM p)
by ORDERS_1:37, ORDERS_1:38;
per cases
( p = 0_ (n,R) or p <> 0_ (n,R) )
;
suppose
p <> 0_ (
n,
R)
;
Lt (LM p) = Lt pthen
LC p <> 0. R
by Y0;
then
(LM p) . (Lt p) <> 0. R
by lemY;
then A:
Lt p in Support (LM p)
by H, POLYNOM1:def 4;
then B:
Support (LM p) = {(Lt p)}
by Z2;
then E:
card (Support (LM p)) = 1
by CARD_1:30;
then C:
len (SgmX ((BagOrder n),(Support (LM p)))) = 1
by I, PRE_POLY:11;
rng (SgmX ((BagOrder n),(Support (LM p)))) = {(Lt p)}
by I, B, PRE_POLY:def 2;
then D:
SgmX (
(BagOrder n),
(Support (LM p)))
= <*(Lt p)*>
by E, I, PRE_POLY:11, FINSEQ_1:39;
E:
LM p <> 0_ (
n,
R)
by A, YY;
thus Lt (LM p) =
<*(Lt p)*> . 1
by C, D, E, defLT
.=
Lt p
;
verum end; end;