Metamath Proof Explorer


Theorem elghomlem2OLD

Description: Obsolete as of 15-Mar-2020. Lemma for elghomOLD . (Contributed by Paul Chapman, 25-Feb-2008) (New usage is discouraged.) (Proof modification is discouraged.)

Ref Expression
Hypothesis elghomlem1OLD.1 𝑆 = { 𝑓 ∣ ( 𝑓 : ran 𝐺 ⟶ ran 𝐻 ∧ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝑓𝑥 ) 𝐻 ( 𝑓𝑦 ) ) = ( 𝑓 ‘ ( 𝑥 𝐺 𝑦 ) ) ) }
Assertion elghomlem2OLD ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ) → ( 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ↔ ( 𝐹 : ran 𝐺 ⟶ ran 𝐻 ∧ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝐹𝑥 ) 𝐻 ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 𝐺 𝑦 ) ) ) ) )

Proof

Step Hyp Ref Expression
1 elghomlem1OLD.1 𝑆 = { 𝑓 ∣ ( 𝑓 : ran 𝐺 ⟶ ran 𝐻 ∧ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝑓𝑥 ) 𝐻 ( 𝑓𝑦 ) ) = ( 𝑓 ‘ ( 𝑥 𝐺 𝑦 ) ) ) }
2 1 elghomlem1OLD ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ) → ( 𝐺 GrpOpHom 𝐻 ) = 𝑆 )
3 2 eleq2d ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ) → ( 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ↔ 𝐹𝑆 ) )
4 elex ( 𝐹𝑆𝐹 ∈ V )
5 feq1 ( 𝑓 = 𝐹 → ( 𝑓 : ran 𝐺 ⟶ ran 𝐻𝐹 : ran 𝐺 ⟶ ran 𝐻 ) )
6 fveq1 ( 𝑓 = 𝐹 → ( 𝑓𝑥 ) = ( 𝐹𝑥 ) )
7 fveq1 ( 𝑓 = 𝐹 → ( 𝑓𝑦 ) = ( 𝐹𝑦 ) )
8 6 7 oveq12d ( 𝑓 = 𝐹 → ( ( 𝑓𝑥 ) 𝐻 ( 𝑓𝑦 ) ) = ( ( 𝐹𝑥 ) 𝐻 ( 𝐹𝑦 ) ) )
9 fveq1 ( 𝑓 = 𝐹 → ( 𝑓 ‘ ( 𝑥 𝐺 𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 𝐺 𝑦 ) ) )
10 8 9 eqeq12d ( 𝑓 = 𝐹 → ( ( ( 𝑓𝑥 ) 𝐻 ( 𝑓𝑦 ) ) = ( 𝑓 ‘ ( 𝑥 𝐺 𝑦 ) ) ↔ ( ( 𝐹𝑥 ) 𝐻 ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 𝐺 𝑦 ) ) ) )
11 10 2ralbidv ( 𝑓 = 𝐹 → ( ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝑓𝑥 ) 𝐻 ( 𝑓𝑦 ) ) = ( 𝑓 ‘ ( 𝑥 𝐺 𝑦 ) ) ↔ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝐹𝑥 ) 𝐻 ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 𝐺 𝑦 ) ) ) )
12 5 11 anbi12d ( 𝑓 = 𝐹 → ( ( 𝑓 : ran 𝐺 ⟶ ran 𝐻 ∧ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝑓𝑥 ) 𝐻 ( 𝑓𝑦 ) ) = ( 𝑓 ‘ ( 𝑥 𝐺 𝑦 ) ) ) ↔ ( 𝐹 : ran 𝐺 ⟶ ran 𝐻 ∧ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝐹𝑥 ) 𝐻 ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 𝐺 𝑦 ) ) ) ) )
13 12 1 elab2g ( 𝐹 ∈ V → ( 𝐹𝑆 ↔ ( 𝐹 : ran 𝐺 ⟶ ran 𝐻 ∧ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝐹𝑥 ) 𝐻 ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 𝐺 𝑦 ) ) ) ) )
14 13 biimpd ( 𝐹 ∈ V → ( 𝐹𝑆 → ( 𝐹 : ran 𝐺 ⟶ ran 𝐻 ∧ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝐹𝑥 ) 𝐻 ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 𝐺 𝑦 ) ) ) ) )
15 4 14 mpcom ( 𝐹𝑆 → ( 𝐹 : ran 𝐺 ⟶ ran 𝐻 ∧ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝐹𝑥 ) 𝐻 ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 𝐺 𝑦 ) ) ) )
16 rnexg ( 𝐺 ∈ GrpOp → ran 𝐺 ∈ V )
17 fex ( ( 𝐹 : ran 𝐺 ⟶ ran 𝐻 ∧ ran 𝐺 ∈ V ) → 𝐹 ∈ V )
18 17 expcom ( ran 𝐺 ∈ V → ( 𝐹 : ran 𝐺 ⟶ ran 𝐻𝐹 ∈ V ) )
19 16 18 syl ( 𝐺 ∈ GrpOp → ( 𝐹 : ran 𝐺 ⟶ ran 𝐻𝐹 ∈ V ) )
20 19 adantrd ( 𝐺 ∈ GrpOp → ( ( 𝐹 : ran 𝐺 ⟶ ran 𝐻 ∧ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝐹𝑥 ) 𝐻 ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 𝐺 𝑦 ) ) ) → 𝐹 ∈ V ) )
21 13 biimprd ( 𝐹 ∈ V → ( ( 𝐹 : ran 𝐺 ⟶ ran 𝐻 ∧ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝐹𝑥 ) 𝐻 ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 𝐺 𝑦 ) ) ) → 𝐹𝑆 ) )
22 20 21 syli ( 𝐺 ∈ GrpOp → ( ( 𝐹 : ran 𝐺 ⟶ ran 𝐻 ∧ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝐹𝑥 ) 𝐻 ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 𝐺 𝑦 ) ) ) → 𝐹𝑆 ) )
23 15 22 impbid2 ( 𝐺 ∈ GrpOp → ( 𝐹𝑆 ↔ ( 𝐹 : ran 𝐺 ⟶ ran 𝐻 ∧ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝐹𝑥 ) 𝐻 ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 𝐺 𝑦 ) ) ) ) )
24 23 adantr ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ) → ( 𝐹𝑆 ↔ ( 𝐹 : ran 𝐺 ⟶ ran 𝐻 ∧ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝐹𝑥 ) 𝐻 ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 𝐺 𝑦 ) ) ) ) )
25 3 24 bitrd ( ( 𝐺 ∈ GrpOp ∧ 𝐻 ∈ GrpOp ) → ( 𝐹 ∈ ( 𝐺 GrpOpHom 𝐻 ) ↔ ( 𝐹 : ran 𝐺 ⟶ ran 𝐻 ∧ ∀ 𝑥 ∈ ran 𝐺𝑦 ∈ ran 𝐺 ( ( 𝐹𝑥 ) 𝐻 ( 𝐹𝑦 ) ) = ( 𝐹 ‘ ( 𝑥 𝐺 𝑦 ) ) ) ) )