Metamath Proof Explorer


Theorem ghomdiv

Description: Group homomorphisms preserve division. (Contributed by Jeff Madsen, 16-Jun-2011)

Ref Expression
Hypotheses ghomdiv.1 𝑋 = ran 𝐺
ghomdiv.2 𝐷 = ( /𝑔𝐺 )
ghomdiv.3 𝐶 = ( /𝑔𝐻 )
Assertion ghomdiv ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( 𝐹 ‘ ( 𝐴 𝐷 𝐵 ) ) = ( ( 𝐹𝐴 ) 𝐶 ( 𝐹𝐵 ) ) )

Proof

Step Hyp Ref Expression
1 ghomdiv.1 𝑋 = ran 𝐺
2 ghomdiv.2 𝐷 = ( /𝑔𝐺 )
3 ghomdiv.3 𝐶 = ( /𝑔𝐻 )
4 simpl2 ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → 𝐻 ∈ GrpOp )
5 eqid ran 𝐻 = ran 𝐻
6 1 5 ghomf ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) → 𝐹 : 𝑋 ⟶ ran 𝐻 )
7 6 ffvelrnda ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ 𝐴𝑋 ) → ( 𝐹𝐴 ) ∈ ran 𝐻 )
8 7 adantrr ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( 𝐹𝐴 ) ∈ ran 𝐻 )
9 6 ffvelrnda ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ 𝐵𝑋 ) → ( 𝐹𝐵 ) ∈ ran 𝐻 )
10 9 adantrl ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( 𝐹𝐵 ) ∈ ran 𝐻 )
11 5 3 grponpcan ( ( 𝐻 ∈ GrpOp ∧ ( 𝐹𝐴 ) ∈ ran 𝐻 ∧ ( 𝐹𝐵 ) ∈ ran 𝐻 ) → ( ( ( 𝐹𝐴 ) 𝐶 ( 𝐹𝐵 ) ) 𝐻 ( 𝐹𝐵 ) ) = ( 𝐹𝐴 ) )
12 4 8 10 11 syl3anc ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( ( ( 𝐹𝐴 ) 𝐶 ( 𝐹𝐵 ) ) 𝐻 ( 𝐹𝐵 ) ) = ( 𝐹𝐴 ) )
13 1 2 grponpcan ( ( 𝐺 ∈ GrpOp ∧ 𝐴𝑋𝐵𝑋 ) → ( ( 𝐴 𝐷 𝐵 ) 𝐺 𝐵 ) = 𝐴 )
14 13 3expb ( ( 𝐺 ∈ GrpOp ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( ( 𝐴 𝐷 𝐵 ) 𝐺 𝐵 ) = 𝐴 )
15 14 3ad2antl1 ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( ( 𝐴 𝐷 𝐵 ) 𝐺 𝐵 ) = 𝐴 )
16 15 fveq2d ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( 𝐹 ‘ ( ( 𝐴 𝐷 𝐵 ) 𝐺 𝐵 ) ) = ( 𝐹𝐴 ) )
17 1 2 grpodivcl ( ( 𝐺 ∈ GrpOp ∧ 𝐴𝑋𝐵𝑋 ) → ( 𝐴 𝐷 𝐵 ) ∈ 𝑋 )
18 17 3expb ( ( 𝐺 ∈ GrpOp ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( 𝐴 𝐷 𝐵 ) ∈ 𝑋 )
19 simprr ( ( 𝐺 ∈ GrpOp ∧ ( 𝐴𝑋𝐵𝑋 ) ) → 𝐵𝑋 )
20 18 19 jca ( ( 𝐺 ∈ GrpOp ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( ( 𝐴 𝐷 𝐵 ) ∈ 𝑋𝐵𝑋 ) )
21 20 3ad2antl1 ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( ( 𝐴 𝐷 𝐵 ) ∈ 𝑋𝐵𝑋 ) )
22 1 ghomlinOLD ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( ( 𝐴 𝐷 𝐵 ) ∈ 𝑋𝐵𝑋 ) ) → ( ( 𝐹 ‘ ( 𝐴 𝐷 𝐵 ) ) 𝐻 ( 𝐹𝐵 ) ) = ( 𝐹 ‘ ( ( 𝐴 𝐷 𝐵 ) 𝐺 𝐵 ) ) )
23 22 eqcomd ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( ( 𝐴 𝐷 𝐵 ) ∈ 𝑋𝐵𝑋 ) ) → ( 𝐹 ‘ ( ( 𝐴 𝐷 𝐵 ) 𝐺 𝐵 ) ) = ( ( 𝐹 ‘ ( 𝐴 𝐷 𝐵 ) ) 𝐻 ( 𝐹𝐵 ) ) )
24 21 23 syldan ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( 𝐹 ‘ ( ( 𝐴 𝐷 𝐵 ) 𝐺 𝐵 ) ) = ( ( 𝐹 ‘ ( 𝐴 𝐷 𝐵 ) ) 𝐻 ( 𝐹𝐵 ) ) )
25 12 16 24 3eqtr2rd ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( ( 𝐹 ‘ ( 𝐴 𝐷 𝐵 ) ) 𝐻 ( 𝐹𝐵 ) ) = ( ( ( 𝐹𝐴 ) 𝐶 ( 𝐹𝐵 ) ) 𝐻 ( 𝐹𝐵 ) ) )
26 18 3ad2antl1 ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( 𝐴 𝐷 𝐵 ) ∈ 𝑋 )
27 6 ffvelrnda ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴 𝐷 𝐵 ) ∈ 𝑋 ) → ( 𝐹 ‘ ( 𝐴 𝐷 𝐵 ) ) ∈ ran 𝐻 )
28 26 27 syldan ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( 𝐹 ‘ ( 𝐴 𝐷 𝐵 ) ) ∈ ran 𝐻 )
29 5 3 grpodivcl ( ( 𝐻 ∈ GrpOp ∧ ( 𝐹𝐴 ) ∈ ran 𝐻 ∧ ( 𝐹𝐵 ) ∈ ran 𝐻 ) → ( ( 𝐹𝐴 ) 𝐶 ( 𝐹𝐵 ) ) ∈ ran 𝐻 )
30 4 8 10 29 syl3anc ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( ( 𝐹𝐴 ) 𝐶 ( 𝐹𝐵 ) ) ∈ ran 𝐻 )
31 5 grporcan ( ( 𝐻 ∈ GrpOp ∧ ( ( 𝐹 ‘ ( 𝐴 𝐷 𝐵 ) ) ∈ ran 𝐻 ∧ ( ( 𝐹𝐴 ) 𝐶 ( 𝐹𝐵 ) ) ∈ ran 𝐻 ∧ ( 𝐹𝐵 ) ∈ ran 𝐻 ) ) → ( ( ( 𝐹 ‘ ( 𝐴 𝐷 𝐵 ) ) 𝐻 ( 𝐹𝐵 ) ) = ( ( ( 𝐹𝐴 ) 𝐶 ( 𝐹𝐵 ) ) 𝐻 ( 𝐹𝐵 ) ) ↔ ( 𝐹 ‘ ( 𝐴 𝐷 𝐵 ) ) = ( ( 𝐹𝐴 ) 𝐶 ( 𝐹𝐵 ) ) ) )
32 4 28 30 10 31 syl13anc ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( ( ( 𝐹 ‘ ( 𝐴 𝐷 𝐵 ) ) 𝐻 ( 𝐹𝐵 ) ) = ( ( ( 𝐹𝐴 ) 𝐶 ( 𝐹𝐵 ) ) 𝐻 ( 𝐹𝐵 ) ) ↔ ( 𝐹 ‘ ( 𝐴 𝐷 𝐵 ) ) = ( ( 𝐹𝐴 ) 𝐶 ( 𝐹𝐵 ) ) ) )
33 25 32 mpbid ( ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ∧ 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ) ∧ ( 𝐴𝑋𝐵𝑋 ) ) → ( 𝐹 ‘ ( 𝐴 𝐷 𝐵 ) ) = ( ( 𝐹𝐴 ) 𝐶 ( 𝐹𝐵 ) ) )