Theorem dfiso2 17833

Description: Alternate definition of an isomorphism of a category, according to definition 3.8 in [Adamek] p. 28. (Contributed by AV, 10-Apr-2020.)

Hypotheses

Ref	Expression
dfiso2.b	⊢ 𝐵 = (Base‘𝐶)
dfiso2.h	⊢ 𝐻 = (Hom ‘𝐶)
dfiso2.c	⊢ (𝜑 → 𝐶 ∈ Cat)
dfiso2.i	⊢ 𝐼 = (Iso‘𝐶)
dfiso2.x	⊢ (𝜑 → 𝑋 ∈ 𝐵)
dfiso2.y	⊢ (𝜑 → 𝑌 ∈ 𝐵)
dfiso2.f	⊢ (𝜑 → 𝐹 ∈ (𝑋𝐻𝑌))
dfiso2.1	⊢ 1 = (Id‘𝐶)
dfiso2.o	⊢ ⚬ = (⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)
dfiso2.p	⊢ ∗ = (⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)

Assertion

Ref	Expression
dfiso2	⊢ (𝜑 → (𝐹 ∈ (𝑋𝐼𝑌) ↔ ∃𝑔 ∈ (𝑌𝐻𝑋)((𝑔 ⚬ 𝐹) = ( 1 ‘𝑋) ∧ (𝐹 ∗ 𝑔) = ( 1 ‘𝑌))))

Distinct variable groups:   𝐶,𝑔   𝑔,𝐹   𝑔,𝐻   𝑔,𝐼   𝑔,𝑋   𝑔,𝑌   ⚬ ,𝑔   ∗ ,𝑔   1 ,𝑔   𝜑,𝑔

Allowed substitution hint:   𝐵(𝑔)

Proof of Theorem dfiso2

Dummy variable 𝑓 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		dfiso2.b	. . . 4 ⊢ 𝐵 = (Base‘𝐶)
2		eqid 2740	. . . 4 ⊢ (Inv‘𝐶) = (Inv‘𝐶)
3		dfiso2.c	. . . 4 ⊢ (𝜑 → 𝐶 ∈ Cat)
4		dfiso2.x	. . . 4 ⊢ (𝜑 → 𝑋 ∈ 𝐵)
5		dfiso2.y	. . . 4 ⊢ (𝜑 → 𝑌 ∈ 𝐵)
6		dfiso2.i	. . . 4 ⊢ 𝐼 = (Iso‘𝐶)
7	1, 2, 3, 4, 5, 6	isoval 17826	. . 3 ⊢ (𝜑 → (𝑋𝐼𝑌) = dom (𝑋(Inv‘𝐶)𝑌))
8	7	eleq2d 2830	. 2 ⊢ (𝜑 → (𝐹 ∈ (𝑋𝐼𝑌) ↔ 𝐹 ∈ dom (𝑋(Inv‘𝐶)𝑌)))
9		eqid 2740	. . . . 5 ⊢ (Sect‘𝐶) = (Sect‘𝐶)
10	1, 2, 3, 4, 5, 9	invfval 17820	. . . 4 ⊢ (𝜑 → (𝑋(Inv‘𝐶)𝑌) = ((𝑋(Sect‘𝐶)𝑌) ∩ ◡(𝑌(Sect‘𝐶)𝑋)))
11	10	dmeqd 5930	. . 3 ⊢ (𝜑 → dom (𝑋(Inv‘𝐶)𝑌) = dom ((𝑋(Sect‘𝐶)𝑌) ∩ ◡(𝑌(Sect‘𝐶)𝑋)))
12	11	eleq2d 2830	. 2 ⊢ (𝜑 → (𝐹 ∈ dom (𝑋(Inv‘𝐶)𝑌) ↔ 𝐹 ∈ dom ((𝑋(Sect‘𝐶)𝑌) ∩ ◡(𝑌(Sect‘𝐶)𝑋))))
13		dfiso2.h	. . . . . . . . 9 ⊢ 𝐻 = (Hom ‘𝐶)
14		eqid 2740	. . . . . . . . 9 ⊢ (comp‘𝐶) = (comp‘𝐶)
15		dfiso2.1	. . . . . . . . 9 ⊢ 1 = (Id‘𝐶)
16	1, 13, 14, 15, 9, 3, 4, 5	sectfval 17812	. . . . . . . 8 ⊢ (𝜑 → (𝑋(Sect‘𝐶)𝑌) = {⟨𝑓, 𝑔⟩ ∣ ((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ (𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋))})
17	1, 13, 14, 15, 9, 3, 5, 4	sectfval 17812	. . . . . . . . . 10 ⊢ (𝜑 → (𝑌(Sect‘𝐶)𝑋) = {⟨𝑔, 𝑓⟩ ∣ ((𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌)) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))})
18	17	cnveqd 5900	. . . . . . . . 9 ⊢ (𝜑 → ◡(𝑌(Sect‘𝐶)𝑋) = ◡{⟨𝑔, 𝑓⟩ ∣ ((𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌)) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))})
19		cnvopab 6169	. . . . . . . . 9 ⊢ ◡{⟨𝑔, 𝑓⟩ ∣ ((𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌)) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))} = {⟨𝑓, 𝑔⟩ ∣ ((𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌)) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))}
20	18, 19	eqtrdi 2796	. . . . . . . 8 ⊢ (𝜑 → ◡(𝑌(Sect‘𝐶)𝑋) = {⟨𝑓, 𝑔⟩ ∣ ((𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌)) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))})
21	16, 20	ineq12d 4242	. . . . . . 7 ⊢ (𝜑 → ((𝑋(Sect‘𝐶)𝑌) ∩ ◡(𝑌(Sect‘𝐶)𝑋)) = ({⟨𝑓, 𝑔⟩ ∣ ((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ (𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋))} ∩ {⟨𝑓, 𝑔⟩ ∣ ((𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌)) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))}))
22		inopab 5853	. . . . . . . 8 ⊢ ({⟨𝑓, 𝑔⟩ ∣ ((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ (𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋))} ∩ {⟨𝑓, 𝑔⟩ ∣ ((𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌)) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))}) = {⟨𝑓, 𝑔⟩ ∣ (((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ (𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋)) ∧ ((𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌)) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))}
23		an4 655	. . . . . . . . . 10 ⊢ ((((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ (𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋)) ∧ ((𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌)) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))) ↔ (((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ (𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌))) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))))
24		an42 656	. . . . . . . . . . . 12 ⊢ (((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ (𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌))) ↔ ((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ (𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋))))
25		anidm 564	. . . . . . . . . . . 12 ⊢ (((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ (𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋))) ↔ (𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)))
26	24, 25	bitri 275	. . . . . . . . . . 11 ⊢ (((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ (𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌))) ↔ (𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)))
27	26	anbi1i 623	. . . . . . . . . 10 ⊢ ((((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ (𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌))) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))) ↔ ((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))))
28	23, 27	bitri 275	. . . . . . . . 9 ⊢ ((((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ (𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋)) ∧ ((𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌)) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))) ↔ ((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))))
29	28	opabbii 5233	. . . . . . . 8 ⊢ {⟨𝑓, 𝑔⟩ ∣ (((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ (𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋)) ∧ ((𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌)) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))} = {⟨𝑓, 𝑔⟩ ∣ ((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))}
30	22, 29	eqtri 2768	. . . . . . 7 ⊢ ({⟨𝑓, 𝑔⟩ ∣ ((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ (𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋))} ∩ {⟨𝑓, 𝑔⟩ ∣ ((𝑔 ∈ (𝑌𝐻𝑋) ∧ 𝑓 ∈ (𝑋𝐻𝑌)) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))}) = {⟨𝑓, 𝑔⟩ ∣ ((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))}
31	21, 30	eqtrdi 2796	. . . . . 6 ⊢ (𝜑 → ((𝑋(Sect‘𝐶)𝑌) ∩ ◡(𝑌(Sect‘𝐶)𝑋)) = {⟨𝑓, 𝑔⟩ ∣ ((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))})
32	31	dmeqd 5930	. . . . 5 ⊢ (𝜑 → dom ((𝑋(Sect‘𝐶)𝑌) ∩ ◡(𝑌(Sect‘𝐶)𝑋)) = dom {⟨𝑓, 𝑔⟩ ∣ ((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))})
33		dmopab 5940	. . . . 5 ⊢ dom {⟨𝑓, 𝑔⟩ ∣ ((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))} = {𝑓 ∣ ∃𝑔((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))}
34	32, 33	eqtrdi 2796	. . . 4 ⊢ (𝜑 → dom ((𝑋(Sect‘𝐶)𝑌) ∩ ◡(𝑌(Sect‘𝐶)𝑋)) = {𝑓 ∣ ∃𝑔((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))})
35	34	eleq2d 2830	. . 3 ⊢ (𝜑 → (𝐹 ∈ dom ((𝑋(Sect‘𝐶)𝑌) ∩ ◡(𝑌(Sect‘𝐶)𝑋)) ↔ 𝐹 ∈ {𝑓 ∣ ∃𝑔((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))}))
36		dfiso2.f	. . . 4 ⊢ (𝜑 → 𝐹 ∈ (𝑋𝐻𝑌))
37		eleq1 2832	. . . . . . . 8 ⊢ (𝑓 = 𝐹 → (𝑓 ∈ (𝑋𝐻𝑌) ↔ 𝐹 ∈ (𝑋𝐻𝑌)))
38	37	anbi1d 630	. . . . . . 7 ⊢ (𝑓 = 𝐹 → ((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ↔ (𝐹 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋))))
39		oveq2 7456	. . . . . . . . 9 ⊢ (𝑓 = 𝐹 → (𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = (𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝐹))
40	39	eqeq1d 2742	. . . . . . . 8 ⊢ (𝑓 = 𝐹 → ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ↔ (𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝐹) = ( 1 ‘𝑋)))
41		oveq1 7455	. . . . . . . . 9 ⊢ (𝑓 = 𝐹 → (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = (𝐹(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔))
42	41	eqeq1d 2742	. . . . . . . 8 ⊢ (𝑓 = 𝐹 → ((𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌) ↔ (𝐹(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))
43	40, 42	anbi12d 631	. . . . . . 7 ⊢ (𝑓 = 𝐹 → (((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)) ↔ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝐹) = ( 1 ‘𝑋) ∧ (𝐹(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))))
44	38, 43	anbi12d 631	. . . . . 6 ⊢ (𝑓 = 𝐹 → (((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))) ↔ ((𝐹 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝐹) = ( 1 ‘𝑋) ∧ (𝐹(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))))
45	44	exbidv 1920	. . . . 5 ⊢ (𝑓 = 𝐹 → (∃𝑔((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))) ↔ ∃𝑔((𝐹 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝐹) = ( 1 ‘𝑋) ∧ (𝐹(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))))
46	45	elabg 3690	. . . 4 ⊢ (𝐹 ∈ (𝑋𝐻𝑌) → (𝐹 ∈ {𝑓 ∣ ∃𝑔((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))} ↔ ∃𝑔((𝐹 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝐹) = ( 1 ‘𝑋) ∧ (𝐹(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))))
47	36, 46	syl 17	. . 3 ⊢ (𝜑 → (𝐹 ∈ {𝑓 ∣ ∃𝑔((𝑓 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝑓) = ( 1 ‘𝑋) ∧ (𝑓(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))} ↔ ∃𝑔((𝐹 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝐹) = ( 1 ‘𝑋) ∧ (𝐹(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)))))
48	36	biantrurd 532	. . . . . . 7 ⊢ (𝜑 → (𝑔 ∈ (𝑌𝐻𝑋) ↔ (𝐹 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋))))
49	48	bicomd 223	. . . . . 6 ⊢ (𝜑 → ((𝐹 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ↔ 𝑔 ∈ (𝑌𝐻𝑋)))
50		dfiso2.o	. . . . . . . . . . 11 ⊢ ⚬ = (⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)
51	50	a1i 11	. . . . . . . . . 10 ⊢ (𝜑 → ⚬ = (⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋))
52	51	eqcomd 2746	. . . . . . . . 9 ⊢ (𝜑 → (⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋) = ⚬ )
53	52	oveqd 7465	. . . . . . . 8 ⊢ (𝜑 → (𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝐹) = (𝑔 ⚬ 𝐹))
54	53	eqeq1d 2742	. . . . . . 7 ⊢ (𝜑 → ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝐹) = ( 1 ‘𝑋) ↔ (𝑔 ⚬ 𝐹) = ( 1 ‘𝑋)))
55		dfiso2.p	. . . . . . . . . . 11 ⊢ ∗ = (⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)
56	55	a1i 11	. . . . . . . . . 10 ⊢ (𝜑 → ∗ = (⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌))
57	56	eqcomd 2746	. . . . . . . . 9 ⊢ (𝜑 → (⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌) = ∗ )
58	57	oveqd 7465	. . . . . . . 8 ⊢ (𝜑 → (𝐹(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = (𝐹 ∗ 𝑔))
59	58	eqeq1d 2742	. . . . . . 7 ⊢ (𝜑 → ((𝐹(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌) ↔ (𝐹 ∗ 𝑔) = ( 1 ‘𝑌)))
60	54, 59	anbi12d 631	. . . . . 6 ⊢ (𝜑 → (((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝐹) = ( 1 ‘𝑋) ∧ (𝐹(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌)) ↔ ((𝑔 ⚬ 𝐹) = ( 1 ‘𝑋) ∧ (𝐹 ∗ 𝑔) = ( 1 ‘𝑌))))
61	49, 60	anbi12d 631	. . . . 5 ⊢ (𝜑 → (((𝐹 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝐹) = ( 1 ‘𝑋) ∧ (𝐹(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))) ↔ (𝑔 ∈ (𝑌𝐻𝑋) ∧ ((𝑔 ⚬ 𝐹) = ( 1 ‘𝑋) ∧ (𝐹 ∗ 𝑔) = ( 1 ‘𝑌)))))
62	61	exbidv 1920	. . . 4 ⊢ (𝜑 → (∃𝑔((𝐹 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝐹) = ( 1 ‘𝑋) ∧ (𝐹(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))) ↔ ∃𝑔(𝑔 ∈ (𝑌𝐻𝑋) ∧ ((𝑔 ⚬ 𝐹) = ( 1 ‘𝑋) ∧ (𝐹 ∗ 𝑔) = ( 1 ‘𝑌)))))
63		df-rex 3077	. . . 4 ⊢ (∃𝑔 ∈ (𝑌𝐻𝑋)((𝑔 ⚬ 𝐹) = ( 1 ‘𝑋) ∧ (𝐹 ∗ 𝑔) = ( 1 ‘𝑌)) ↔ ∃𝑔(𝑔 ∈ (𝑌𝐻𝑋) ∧ ((𝑔 ⚬ 𝐹) = ( 1 ‘𝑋) ∧ (𝐹 ∗ 𝑔) = ( 1 ‘𝑌))))
64	62, 63	bitr4di 289	. . 3 ⊢ (𝜑 → (∃𝑔((𝐹 ∈ (𝑋𝐻𝑌) ∧ 𝑔 ∈ (𝑌𝐻𝑋)) ∧ ((𝑔(⟨𝑋, 𝑌⟩(comp‘𝐶)𝑋)𝐹) = ( 1 ‘𝑋) ∧ (𝐹(⟨𝑌, 𝑋⟩(comp‘𝐶)𝑌)𝑔) = ( 1 ‘𝑌))) ↔ ∃𝑔 ∈ (𝑌𝐻𝑋)((𝑔 ⚬ 𝐹) = ( 1 ‘𝑋) ∧ (𝐹 ∗ 𝑔) = ( 1 ‘𝑌))))
65	35, 47, 64	3bitrd 305	. 2 ⊢ (𝜑 → (𝐹 ∈ dom ((𝑋(Sect‘𝐶)𝑌) ∩ ◡(𝑌(Sect‘𝐶)𝑋)) ↔ ∃𝑔 ∈ (𝑌𝐻𝑋)((𝑔 ⚬ 𝐹) = ( 1 ‘𝑋) ∧ (𝐹 ∗ 𝑔) = ( 1 ‘𝑌))))
66	8, 12, 65	3bitrd 305	1 ⊢ (𝜑 → (𝐹 ∈ (𝑋𝐼𝑌) ↔ ∃𝑔 ∈ (𝑌𝐻𝑋)((𝑔 ⚬ 𝐹) = ( 1 ‘𝑋) ∧ (𝐹 ∗ 𝑔) = ( 1 ‘𝑌))))

Syntax hints:   → wi 4   ↔ wb 206   ∧ wa 395   = wceq 1537  ∃wex 1777   ∈ wcel 2108  {cab 2717  ∃wrex 3076   ∩ cin 3975  ⟨cop 4654  {copab 5228  ^◡ccnv 5699  dom cdm 5700  ‘cfv 6573  (class class class)co 7448  Basecbs 17258  Hom chom 17322  compcco 17323  Catccat 17722  Idccid 17723  Sectcsect 17805  Invcinv 17806  Isociso 17807

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1793  ax-4 1807  ax-5 1909  ax-6 1967  ax-7 2007  ax-8 2110  ax-9 2118  ax-10 2141  ax-11 2158  ax-12 2178  ax-ext 2711  ax-rep 5303  ax-sep 5317  ax-nul 5324  ax-pow 5383  ax-pr 5447  ax-un 7770

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 847  df-3an 1089  df-tru 1540  df-fal 1550  df-ex 1778  df-nf 1782  df-sb 2065  df-mo 2543  df-eu 2572  df-clab 2718  df-cleq 2732  df-clel 2819  df-nfc 2895  df-ne 2947  df-ral 3068  df-rex 3077  df-reu 3389  df-rab 3444  df-v 3490  df-sbc 3805  df-csb 3922  df-dif 3979  df-un 3981  df-in 3983  df-ss 3993  df-nul 4353  df-if 4549  df-pw 4624  df-sn 4649  df-pr 4651  df-op 4655  df-uni 4932  df-iun 5017  df-br 5167  df-opab 5229  df-mpt 5250  df-id 5593  df-xp 5706  df-rel 5707  df-cnv 5708  df-co 5709  df-dm 5710  df-rn 5711  df-res 5712  df-ima 5713  df-iota 6525  df-fun 6575  df-fn 6576  df-f 6577  df-f1 6578  df-fo 6579  df-f1o 6580  df-fv 6581  df-ov 7451  df-oprab 7452  df-mpo 7453  df-1st 8030  df-2nd 8031  df-sect 17808  df-inv 17809  df-iso 17810

This theorem is referenced by:  dfiso3  17834