Metamath Proof Explorer


Theorem cayleyhamilton0

Description: The Cayley-Hamilton theorem: A matrix over a commutative ring "satisfies its own characteristic equation". This version of cayleyhamilton provides definitions not used in the theorem itself, but in its proof to make it clearer, more readable and shorter compared with a proof without them (see cayleyhamiltonALT )! (Contributed by AV, 25-Nov-2019) (Revised by AV, 15-Dec-2019)

Ref Expression
Hypotheses cayleyhamilton0.a 𝐴 = ( 𝑁 Mat 𝑅 )
cayleyhamilton0.b 𝐵 = ( Base ‘ 𝐴 )
cayleyhamilton0.0 0 = ( 0g𝐴 )
cayleyhamilton0.1 1 = ( 1r𝐴 )
cayleyhamilton0.m = ( ·𝑠𝐴 )
cayleyhamilton0.e1 = ( .g ‘ ( mulGrp ‘ 𝐴 ) )
cayleyhamilton0.c 𝐶 = ( 𝑁 CharPlyMat 𝑅 )
cayleyhamilton0.k 𝐾 = ( coe1 ‘ ( 𝐶𝑀 ) )
cayleyhamilton0.p 𝑃 = ( Poly1𝑅 )
cayleyhamilton0.y 𝑌 = ( 𝑁 Mat 𝑃 )
cayleyhamilton0.r × = ( .r𝑌 )
cayleyhamilton0.s = ( -g𝑌 )
cayleyhamilton0.z 𝑍 = ( 0g𝑌 )
cayleyhamilton0.w 𝑊 = ( Base ‘ 𝑌 )
cayleyhamilton0.e2 𝐸 = ( .g ‘ ( mulGrp ‘ 𝑌 ) )
cayleyhamilton0.t 𝑇 = ( 𝑁 matToPolyMat 𝑅 )
cayleyhamilton0.g 𝐺 = ( 𝑛 ∈ ℕ0 ↦ if ( 𝑛 = 0 , ( 𝑍 ( ( 𝑇𝑀 ) × ( 𝑇 ‘ ( 𝑏 ‘ 0 ) ) ) ) , if ( 𝑛 = ( 𝑠 + 1 ) , ( 𝑇 ‘ ( 𝑏𝑠 ) ) , if ( ( 𝑠 + 1 ) < 𝑛 , 𝑍 , ( ( 𝑇 ‘ ( 𝑏 ‘ ( 𝑛 − 1 ) ) ) ( ( 𝑇𝑀 ) × ( 𝑇 ‘ ( 𝑏𝑛 ) ) ) ) ) ) ) )
cayleyhamilton0.u 𝑈 = ( 𝑁 cPolyMatToMat 𝑅 )
Assertion cayleyhamilton0 ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) → ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝐾𝑛 ) ( 𝑛 𝑀 ) ) ) ) = 0 )

Proof

Step Hyp Ref Expression
1 cayleyhamilton0.a 𝐴 = ( 𝑁 Mat 𝑅 )
2 cayleyhamilton0.b 𝐵 = ( Base ‘ 𝐴 )
3 cayleyhamilton0.0 0 = ( 0g𝐴 )
4 cayleyhamilton0.1 1 = ( 1r𝐴 )
5 cayleyhamilton0.m = ( ·𝑠𝐴 )
6 cayleyhamilton0.e1 = ( .g ‘ ( mulGrp ‘ 𝐴 ) )
7 cayleyhamilton0.c 𝐶 = ( 𝑁 CharPlyMat 𝑅 )
8 cayleyhamilton0.k 𝐾 = ( coe1 ‘ ( 𝐶𝑀 ) )
9 cayleyhamilton0.p 𝑃 = ( Poly1𝑅 )
10 cayleyhamilton0.y 𝑌 = ( 𝑁 Mat 𝑃 )
11 cayleyhamilton0.r × = ( .r𝑌 )
12 cayleyhamilton0.s = ( -g𝑌 )
13 cayleyhamilton0.z 𝑍 = ( 0g𝑌 )
14 cayleyhamilton0.w 𝑊 = ( Base ‘ 𝑌 )
15 cayleyhamilton0.e2 𝐸 = ( .g ‘ ( mulGrp ‘ 𝑌 ) )
16 cayleyhamilton0.t 𝑇 = ( 𝑁 matToPolyMat 𝑅 )
17 cayleyhamilton0.g 𝐺 = ( 𝑛 ∈ ℕ0 ↦ if ( 𝑛 = 0 , ( 𝑍 ( ( 𝑇𝑀 ) × ( 𝑇 ‘ ( 𝑏 ‘ 0 ) ) ) ) , if ( 𝑛 = ( 𝑠 + 1 ) , ( 𝑇 ‘ ( 𝑏𝑠 ) ) , if ( ( 𝑠 + 1 ) < 𝑛 , 𝑍 , ( ( 𝑇 ‘ ( 𝑏 ‘ ( 𝑛 − 1 ) ) ) ( ( 𝑇𝑀 ) × ( 𝑇 ‘ ( 𝑏𝑛 ) ) ) ) ) ) ) )
18 cayleyhamilton0.u 𝑈 = ( 𝑁 cPolyMatToMat 𝑅 )
19 eqid ( 𝐶𝑀 ) = ( 𝐶𝑀 )
20 1 2 9 10 11 12 13 16 7 19 17 14 4 5 18 6 15 cayhamlem4 ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) → ∃ 𝑠 ∈ ℕ ∃ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( ( coe1 ‘ ( 𝐶𝑀 ) ) ‘ 𝑛 ) ( 𝑛 𝑀 ) ) ) ) = ( 𝑈 ‘ ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) ) )
21 8 eqcomi ( coe1 ‘ ( 𝐶𝑀 ) ) = 𝐾
22 21 a1i ( ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) ∧ 𝑛 ∈ ℕ0 ) → ( coe1 ‘ ( 𝐶𝑀 ) ) = 𝐾 )
23 22 fveq1d ( ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) ∧ 𝑛 ∈ ℕ0 ) → ( ( coe1 ‘ ( 𝐶𝑀 ) ) ‘ 𝑛 ) = ( 𝐾𝑛 ) )
24 23 oveq1d ( ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) ∧ 𝑛 ∈ ℕ0 ) → ( ( ( coe1 ‘ ( 𝐶𝑀 ) ) ‘ 𝑛 ) ( 𝑛 𝑀 ) ) = ( ( 𝐾𝑛 ) ( 𝑛 𝑀 ) ) )
25 24 mpteq2dva ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) → ( 𝑛 ∈ ℕ0 ↦ ( ( ( coe1 ‘ ( 𝐶𝑀 ) ) ‘ 𝑛 ) ( 𝑛 𝑀 ) ) ) = ( 𝑛 ∈ ℕ0 ↦ ( ( 𝐾𝑛 ) ( 𝑛 𝑀 ) ) ) )
26 25 oveq2d ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) → ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( ( coe1 ‘ ( 𝐶𝑀 ) ) ‘ 𝑛 ) ( 𝑛 𝑀 ) ) ) ) = ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝐾𝑛 ) ( 𝑛 𝑀 ) ) ) ) )
27 26 eqeq1d ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) → ( ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( ( coe1 ‘ ( 𝐶𝑀 ) ) ‘ 𝑛 ) ( 𝑛 𝑀 ) ) ) ) = ( 𝑈 ‘ ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) ) ↔ ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝐾𝑛 ) ( 𝑛 𝑀 ) ) ) ) = ( 𝑈 ‘ ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) ) ) )
28 27 biimpa ( ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) ∧ ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( ( coe1 ‘ ( 𝐶𝑀 ) ) ‘ 𝑛 ) ( 𝑛 𝑀 ) ) ) ) = ( 𝑈 ‘ ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) ) ) → ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝐾𝑛 ) ( 𝑛 𝑀 ) ) ) ) = ( 𝑈 ‘ ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) ) )
29 oveq1 ( 𝑛 = 𝑙 → ( 𝑛 𝐸 ( 𝑇𝑀 ) ) = ( 𝑙 𝐸 ( 𝑇𝑀 ) ) )
30 fveq2 ( 𝑛 = 𝑙 → ( 𝐺𝑛 ) = ( 𝐺𝑙 ) )
31 29 30 oveq12d ( 𝑛 = 𝑙 → ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) = ( ( 𝑙 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑙 ) ) )
32 31 cbvmptv ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) = ( 𝑙 ∈ ℕ0 ↦ ( ( 𝑙 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑙 ) ) )
33 32 oveq2i ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) = ( 𝑌 Σg ( 𝑙 ∈ ℕ0 ↦ ( ( 𝑙 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑙 ) ) ) )
34 1 2 9 10 11 12 13 16 17 15 cayhamlem1 ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) → ( 𝑌 Σg ( 𝑙 ∈ ℕ0 ↦ ( ( 𝑙 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑙 ) ) ) ) = 𝑍 )
35 33 34 syl5eq ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) → ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) = 𝑍 )
36 fveq2 ( ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) = 𝑍 → ( 𝑈 ‘ ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) ) = ( 𝑈𝑍 ) )
37 crngring ( 𝑅 ∈ CRing → 𝑅 ∈ Ring )
38 37 anim2i ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ) → ( 𝑁 ∈ Fin ∧ 𝑅 ∈ Ring ) )
39 38 3adant3 ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) → ( 𝑁 ∈ Fin ∧ 𝑅 ∈ Ring ) )
40 eqid ( 0g𝐴 ) = ( 0g𝐴 )
41 1 18 9 10 40 13 m2cpminv0 ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ Ring ) → ( 𝑈𝑍 ) = ( 0g𝐴 ) )
42 39 41 syl ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) → ( 𝑈𝑍 ) = ( 0g𝐴 ) )
43 42 3 eqtr4di ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) → ( 𝑈𝑍 ) = 0 )
44 43 adantr ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) → ( 𝑈𝑍 ) = 0 )
45 36 44 sylan9eqr ( ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) ∧ ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) = 𝑍 ) → ( 𝑈 ‘ ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) ) = 0 )
46 35 45 mpdan ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) → ( 𝑈 ‘ ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) ) = 0 )
47 46 adantr ( ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) ∧ ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( ( coe1 ‘ ( 𝐶𝑀 ) ) ‘ 𝑛 ) ( 𝑛 𝑀 ) ) ) ) = ( 𝑈 ‘ ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) ) ) → ( 𝑈 ‘ ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) ) = 0 )
48 28 47 eqtrd ( ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) ∧ ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( ( coe1 ‘ ( 𝐶𝑀 ) ) ‘ 𝑛 ) ( 𝑛 𝑀 ) ) ) ) = ( 𝑈 ‘ ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) ) ) → ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝐾𝑛 ) ( 𝑛 𝑀 ) ) ) ) = 0 )
49 48 ex ( ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) ∧ ( 𝑠 ∈ ℕ ∧ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ) ) → ( ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( ( coe1 ‘ ( 𝐶𝑀 ) ) ‘ 𝑛 ) ( 𝑛 𝑀 ) ) ) ) = ( 𝑈 ‘ ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) ) → ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝐾𝑛 ) ( 𝑛 𝑀 ) ) ) ) = 0 ) )
50 49 rexlimdvva ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) → ( ∃ 𝑠 ∈ ℕ ∃ 𝑏 ∈ ( 𝐵m ( 0 ... 𝑠 ) ) ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( ( coe1 ‘ ( 𝐶𝑀 ) ) ‘ 𝑛 ) ( 𝑛 𝑀 ) ) ) ) = ( 𝑈 ‘ ( 𝑌 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝑛 𝐸 ( 𝑇𝑀 ) ) × ( 𝐺𝑛 ) ) ) ) ) → ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝐾𝑛 ) ( 𝑛 𝑀 ) ) ) ) = 0 ) )
51 20 50 mpd ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀𝐵 ) → ( 𝐴 Σg ( 𝑛 ∈ ℕ0 ↦ ( ( 𝐾𝑛 ) ( 𝑛 𝑀 ) ) ) ) = 0 )