let K be algebraic-closed Field; for V1 being non trivial finite-dimensional VectSp of K
for f being linear-transformation of V1,V1 holds f is with_eigenvalues
let V1 be non trivial finite-dimensional VectSp of K; for f being linear-transformation of V1,V1 holds f is with_eigenvalues
let f be linear-transformation of V1,V1; f is with_eigenvalues
consider b1 being OrdBasis of V1;
set AutA = AutMt f,b1,b1;
consider P being Polynomial of K such that
A1:
len P = (len b1) + 1
and
A2:
for x being Element of K holds eval P,x = Det ((AutMt f,b1,b1) + (x * (1. K,(len b1))))
by Th8;
( dim V1 <> 0 & dim V1 = len b1 )
by MATRLIN2:21, MATRLIN2:42;
then
len P > 1 + 0
by A1, XREAL_1:10;
then
P is with_roots
by POLYNOM5:def 8;
then consider L being Element of K such that
A3:
L is_a_root_of P
by POLYNOM5:def 7;
A4: Mx2Tran (L * (AutMt (id V1),b1,b1)),b1,b1 =
L * (Mx2Tran (AutMt (id V1),b1,b1),b1,b1)
by MATRLIN2:38
.=
L * (id V1)
by MATRLIN2:34
.=
Mx2Tran (AutMt (L * (id V1)),b1,b1),b1,b1
by MATRLIN2:34
;
0. K =
eval P,L
by A3, POLYNOM5:def 6
.=
Det ((AutMt f,b1,b1) + (L * (1. K,(len b1))))
by A2
.=
Det ((AutMt f,b1,b1) + (L * (AutMt (id V1),b1,b1)))
by MATRLIN2:28
.=
Det ((AutMt f,b1,b1) + (AutMt (L * (id V1)),b1,b1))
by A4, MATRLIN2:39
.=
Det (AutMt (f + (L * (id V1))),b1,b1)
by MATRLIN:47
.=
Det (AutMt (f + ((- (- L)) * (id V1))),b1,b1)
by RLVECT_1:30
.=
Det (AutEqMt (f + ((- (- L)) * (id V1))),b1,b1)
by MATRLIN2:def 2
;
hence
f is with_eigenvalues
by Th15; verum