let R be non degenerated unital doubleLoopStr ; for n being non trivial Nat holds LC (X^ (n,R)) = 1. R
let n be non trivial Nat; LC (X^ (n,R)) = 1. R
set q = X^ (n,R);
A: n =
deg (X^ (n,R))
by Lm12
.=
(len (X^ (n,R))) - 1
by HURWITZ:def 2
;
then
n + 1 = len (X^ (n,R))
;
then
(len (X^ (n,R))) -' 1 = n
by A, XREAL_1:233, NAT_1:11;
then
(X^ (n,R)) . ((len (X^ (n,R))) -' 1) = 1. R
by Lm10;
hence
LC (X^ (n,R)) = 1. R
by RATFUNC1:def 6; verum