Metamath Proof Explorer


Theorem chpscmat0

Description: The characteristic polynomial of a (nonempty!) scalar matrix, expressed with its diagonal element. (Contributed by AV, 21-Aug-2019)

Ref Expression
Hypotheses chp0mat.c
|- C = ( N CharPlyMat R )
chp0mat.p
|- P = ( Poly1 ` R )
chp0mat.a
|- A = ( N Mat R )
chp0mat.x
|- X = ( var1 ` R )
chp0mat.g
|- G = ( mulGrp ` P )
chp0mat.m
|- .^ = ( .g ` G )
chpscmat.d
|- D = { m e. ( Base ` A ) | E. c e. ( Base ` R ) A. i e. N A. j e. N ( i m j ) = if ( i = j , c , ( 0g ` R ) ) }
chpscmat.s
|- S = ( algSc ` P )
chpscmat.m
|- .- = ( -g ` P )
Assertion chpscmat0
|- ( ( ( N e. Fin /\ R e. CRing ) /\ ( M e. D /\ I e. N /\ A. n e. N ( n M n ) = ( I M I ) ) ) -> ( C ` M ) = ( ( # ` N ) .^ ( X .- ( S ` ( I M I ) ) ) ) )

Proof

Step Hyp Ref Expression
1 chp0mat.c
 |-  C = ( N CharPlyMat R )
2 chp0mat.p
 |-  P = ( Poly1 ` R )
3 chp0mat.a
 |-  A = ( N Mat R )
4 chp0mat.x
 |-  X = ( var1 ` R )
5 chp0mat.g
 |-  G = ( mulGrp ` P )
6 chp0mat.m
 |-  .^ = ( .g ` G )
7 chpscmat.d
 |-  D = { m e. ( Base ` A ) | E. c e. ( Base ` R ) A. i e. N A. j e. N ( i m j ) = if ( i = j , c , ( 0g ` R ) ) }
8 chpscmat.s
 |-  S = ( algSc ` P )
9 chpscmat.m
 |-  .- = ( -g ` P )
10 1 2 3 4 5 6 7 8 9 chpscmat
 |-  ( ( ( N e. Fin /\ R e. CRing ) /\ ( M e. D /\ I e. N /\ A. n e. N ( n M n ) = ( I M I ) ) ) -> ( C ` M ) = ( ( # ` N ) .^ ( X .- ( S ` ( I M I ) ) ) ) )