Metamath Proof Explorer


Theorem zrhpsgnmhm

Description: Embedding of permutation signs into an arbitrary ring is a homomorphism. (Contributed by SO, 9-Jul-2018)

Ref Expression
Assertion zrhpsgnmhm ( ( 𝑅 ∈ Ring ∧ 𝐴 ∈ Fin ) → ( ( ℤRHom ‘ 𝑅 ) ∘ ( pmSgn ‘ 𝐴 ) ) ∈ ( ( SymGrp ‘ 𝐴 ) MndHom ( mulGrp ‘ 𝑅 ) ) )

Proof

Step Hyp Ref Expression
1 eqid ( ℤRHom ‘ 𝑅 ) = ( ℤRHom ‘ 𝑅 )
2 1 zrhrhm ( 𝑅 ∈ Ring → ( ℤRHom ‘ 𝑅 ) ∈ ( ℤring RingHom 𝑅 ) )
3 eqid ( mulGrp ‘ ℤring ) = ( mulGrp ‘ ℤring )
4 eqid ( mulGrp ‘ 𝑅 ) = ( mulGrp ‘ 𝑅 )
5 3 4 rhmmhm ( ( ℤRHom ‘ 𝑅 ) ∈ ( ℤring RingHom 𝑅 ) → ( ℤRHom ‘ 𝑅 ) ∈ ( ( mulGrp ‘ ℤring ) MndHom ( mulGrp ‘ 𝑅 ) ) )
6 2 5 syl ( 𝑅 ∈ Ring → ( ℤRHom ‘ 𝑅 ) ∈ ( ( mulGrp ‘ ℤring ) MndHom ( mulGrp ‘ 𝑅 ) ) )
7 eqid ( SymGrp ‘ 𝐴 ) = ( SymGrp ‘ 𝐴 )
8 eqid ( pmSgn ‘ 𝐴 ) = ( pmSgn ‘ 𝐴 )
9 eqid ( ( mulGrp ‘ ℂfld ) ↾s { 1 , - 1 } ) = ( ( mulGrp ‘ ℂfld ) ↾s { 1 , - 1 } )
10 7 8 9 psgnghm2 ( 𝐴 ∈ Fin → ( pmSgn ‘ 𝐴 ) ∈ ( ( SymGrp ‘ 𝐴 ) GrpHom ( ( mulGrp ‘ ℂfld ) ↾s { 1 , - 1 } ) ) )
11 ghmmhm ( ( pmSgn ‘ 𝐴 ) ∈ ( ( SymGrp ‘ 𝐴 ) GrpHom ( ( mulGrp ‘ ℂfld ) ↾s { 1 , - 1 } ) ) → ( pmSgn ‘ 𝐴 ) ∈ ( ( SymGrp ‘ 𝐴 ) MndHom ( ( mulGrp ‘ ℂfld ) ↾s { 1 , - 1 } ) ) )
12 10 11 syl ( 𝐴 ∈ Fin → ( pmSgn ‘ 𝐴 ) ∈ ( ( SymGrp ‘ 𝐴 ) MndHom ( ( mulGrp ‘ ℂfld ) ↾s { 1 , - 1 } ) ) )
13 eqid ( ( mulGrp ‘ ℂfld ) ↾s ( ℂ ∖ { 0 } ) ) = ( ( mulGrp ‘ ℂfld ) ↾s ( ℂ ∖ { 0 } ) )
14 13 cnmsgnsubg { 1 , - 1 } ∈ ( SubGrp ‘ ( ( mulGrp ‘ ℂfld ) ↾s ( ℂ ∖ { 0 } ) ) )
15 subgsubm ( { 1 , - 1 } ∈ ( SubGrp ‘ ( ( mulGrp ‘ ℂfld ) ↾s ( ℂ ∖ { 0 } ) ) ) → { 1 , - 1 } ∈ ( SubMnd ‘ ( ( mulGrp ‘ ℂfld ) ↾s ( ℂ ∖ { 0 } ) ) ) )
16 14 15 ax-mp { 1 , - 1 } ∈ ( SubMnd ‘ ( ( mulGrp ‘ ℂfld ) ↾s ( ℂ ∖ { 0 } ) ) )
17 cnring fld ∈ Ring
18 cnfldbas ℂ = ( Base ‘ ℂfld )
19 cnfld0 0 = ( 0g ‘ ℂfld )
20 cndrng fld ∈ DivRing
21 18 19 20 drngui ( ℂ ∖ { 0 } ) = ( Unit ‘ ℂfld )
22 eqid ( mulGrp ‘ ℂfld ) = ( mulGrp ‘ ℂfld )
23 21 22 unitsubm ( ℂfld ∈ Ring → ( ℂ ∖ { 0 } ) ∈ ( SubMnd ‘ ( mulGrp ‘ ℂfld ) ) )
24 13 subsubm ( ( ℂ ∖ { 0 } ) ∈ ( SubMnd ‘ ( mulGrp ‘ ℂfld ) ) → ( { 1 , - 1 } ∈ ( SubMnd ‘ ( ( mulGrp ‘ ℂfld ) ↾s ( ℂ ∖ { 0 } ) ) ) ↔ ( { 1 , - 1 } ∈ ( SubMnd ‘ ( mulGrp ‘ ℂfld ) ) ∧ { 1 , - 1 } ⊆ ( ℂ ∖ { 0 } ) ) ) )
25 17 23 24 mp2b ( { 1 , - 1 } ∈ ( SubMnd ‘ ( ( mulGrp ‘ ℂfld ) ↾s ( ℂ ∖ { 0 } ) ) ) ↔ ( { 1 , - 1 } ∈ ( SubMnd ‘ ( mulGrp ‘ ℂfld ) ) ∧ { 1 , - 1 } ⊆ ( ℂ ∖ { 0 } ) ) )
26 16 25 mpbi ( { 1 , - 1 } ∈ ( SubMnd ‘ ( mulGrp ‘ ℂfld ) ) ∧ { 1 , - 1 } ⊆ ( ℂ ∖ { 0 } ) )
27 26 simpli { 1 , - 1 } ∈ ( SubMnd ‘ ( mulGrp ‘ ℂfld ) )
28 1z 1 ∈ ℤ
29 neg1z - 1 ∈ ℤ
30 prssi ( ( 1 ∈ ℤ ∧ - 1 ∈ ℤ ) → { 1 , - 1 } ⊆ ℤ )
31 28 29 30 mp2an { 1 , - 1 } ⊆ ℤ
32 zsubrg ℤ ∈ ( SubRing ‘ ℂfld )
33 22 subrgsubm ( ℤ ∈ ( SubRing ‘ ℂfld ) → ℤ ∈ ( SubMnd ‘ ( mulGrp ‘ ℂfld ) ) )
34 zringmpg ( ( mulGrp ‘ ℂfld ) ↾s ℤ ) = ( mulGrp ‘ ℤring )
35 34 eqcomi ( mulGrp ‘ ℤring ) = ( ( mulGrp ‘ ℂfld ) ↾s ℤ )
36 35 subsubm ( ℤ ∈ ( SubMnd ‘ ( mulGrp ‘ ℂfld ) ) → ( { 1 , - 1 } ∈ ( SubMnd ‘ ( mulGrp ‘ ℤring ) ) ↔ ( { 1 , - 1 } ∈ ( SubMnd ‘ ( mulGrp ‘ ℂfld ) ) ∧ { 1 , - 1 } ⊆ ℤ ) ) )
37 32 33 36 mp2b ( { 1 , - 1 } ∈ ( SubMnd ‘ ( mulGrp ‘ ℤring ) ) ↔ ( { 1 , - 1 } ∈ ( SubMnd ‘ ( mulGrp ‘ ℂfld ) ) ∧ { 1 , - 1 } ⊆ ℤ ) )
38 27 31 37 mpbir2an { 1 , - 1 } ∈ ( SubMnd ‘ ( mulGrp ‘ ℤring ) )
39 zex ℤ ∈ V
40 ressabs ( ( ℤ ∈ V ∧ { 1 , - 1 } ⊆ ℤ ) → ( ( ( mulGrp ‘ ℂfld ) ↾s ℤ ) ↾s { 1 , - 1 } ) = ( ( mulGrp ‘ ℂfld ) ↾s { 1 , - 1 } ) )
41 39 31 40 mp2an ( ( ( mulGrp ‘ ℂfld ) ↾s ℤ ) ↾s { 1 , - 1 } ) = ( ( mulGrp ‘ ℂfld ) ↾s { 1 , - 1 } )
42 34 oveq1i ( ( ( mulGrp ‘ ℂfld ) ↾s ℤ ) ↾s { 1 , - 1 } ) = ( ( mulGrp ‘ ℤring ) ↾s { 1 , - 1 } )
43 41 42 eqtr3i ( ( mulGrp ‘ ℂfld ) ↾s { 1 , - 1 } ) = ( ( mulGrp ‘ ℤring ) ↾s { 1 , - 1 } )
44 43 resmhm2 ( ( ( pmSgn ‘ 𝐴 ) ∈ ( ( SymGrp ‘ 𝐴 ) MndHom ( ( mulGrp ‘ ℂfld ) ↾s { 1 , - 1 } ) ) ∧ { 1 , - 1 } ∈ ( SubMnd ‘ ( mulGrp ‘ ℤring ) ) ) → ( pmSgn ‘ 𝐴 ) ∈ ( ( SymGrp ‘ 𝐴 ) MndHom ( mulGrp ‘ ℤring ) ) )
45 12 38 44 sylancl ( 𝐴 ∈ Fin → ( pmSgn ‘ 𝐴 ) ∈ ( ( SymGrp ‘ 𝐴 ) MndHom ( mulGrp ‘ ℤring ) ) )
46 mhmco ( ( ( ℤRHom ‘ 𝑅 ) ∈ ( ( mulGrp ‘ ℤring ) MndHom ( mulGrp ‘ 𝑅 ) ) ∧ ( pmSgn ‘ 𝐴 ) ∈ ( ( SymGrp ‘ 𝐴 ) MndHom ( mulGrp ‘ ℤring ) ) ) → ( ( ℤRHom ‘ 𝑅 ) ∘ ( pmSgn ‘ 𝐴 ) ) ∈ ( ( SymGrp ‘ 𝐴 ) MndHom ( mulGrp ‘ 𝑅 ) ) )
47 6 45 46 syl2an ( ( 𝑅 ∈ Ring ∧ 𝐴 ∈ Fin ) → ( ( ℤRHom ‘ 𝑅 ) ∘ ( pmSgn ‘ 𝐴 ) ) ∈ ( ( SymGrp ‘ 𝐴 ) MndHom ( mulGrp ‘ 𝑅 ) ) )