Theorem hashfacen 14603

Description: The number of bijections between two sets is a cardinal invariant. (Contributed by Mario Carneiro, 21-Jan-2015.) (Proof shortened by AV, 7-Aug-2024.)

Assertion

Ref	Expression
hashfacen	⊢ ((𝐴 ≈ 𝐵 ∧ 𝐶 ≈ 𝐷) → {𝑓 ∣ 𝑓:𝐴–1-1-onto→𝐶} ≈ {𝑓 ∣ 𝑓:𝐵–1-1-onto→𝐷})

Distinct variable groups:   𝐴,𝑓   𝐵,𝑓   𝐶,𝑓   𝐷,𝑓

Proof of Theorem hashfacen

Dummy variables 𝑔 ℎ 𝑥 𝑦 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		bren 8987	. 2 ⊢ (𝐴 ≈ 𝐵 ↔ ∃𝑔 𝑔:𝐴–1-1-onto→𝐵)
2		bren 8987	. 2 ⊢ (𝐶 ≈ 𝐷 ↔ ∃ℎ ℎ:𝐶–1-1-onto→𝐷)
3		exdistrv 1987	. . 3 ⊢ (∃𝑔∃ℎ(𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ↔ (∃𝑔 𝑔:𝐴–1-1-onto→𝐵 ∧ ∃ℎ ℎ:𝐶–1-1-onto→𝐷))
4		f1osetex 8885	. . . . . 6 ⊢ {𝑓 ∣ 𝑓:𝐴–1-1-onto→𝐶} ∈ V
5	4	a1i 11	. . . . 5 ⊢ ((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) → {𝑓 ∣ 𝑓:𝐴–1-1-onto→𝐶} ∈ V)
6		f1osetex 8885	. . . . . 6 ⊢ {𝑓 ∣ 𝑓:𝐵–1-1-onto→𝐷} ∈ V
7	6	a1i 11	. . . . 5 ⊢ ((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) → {𝑓 ∣ 𝑓:𝐵–1-1-onto→𝐷} ∈ V)
8		f1oco 6849	. . . . . . . . 9 ⊢ ((ℎ:𝐶–1-1-onto→𝐷 ∧ 𝑥:𝐴–1-1-onto→𝐶) → (ℎ ∘ 𝑥):𝐴–1-1-onto→𝐷)
9	8	adantll 727	. . . . . . . 8 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ 𝑥:𝐴–1-1-onto→𝐶) → (ℎ ∘ 𝑥):𝐴–1-1-onto→𝐷)
10		f1ocnv 6838	. . . . . . . . 9 ⊢ (𝑔:𝐴–1-1-onto→𝐵 → ◡𝑔:𝐵–1-1-onto→𝐴)
11	10	ad2antrr 739	. . . . . . . 8 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ 𝑥:𝐴–1-1-onto→𝐶) → ◡𝑔:𝐵–1-1-onto→𝐴)
12		f1oco 6849	. . . . . . . 8 ⊢ (((ℎ ∘ 𝑥):𝐴–1-1-onto→𝐷 ∧ ◡𝑔:𝐵–1-1-onto→𝐴) → ((ℎ ∘ 𝑥) ∘ ◡𝑔):𝐵–1-1-onto→𝐷)
13	9, 11, 12	syl2anc 596	. . . . . . 7 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ 𝑥:𝐴–1-1-onto→𝐶) → ((ℎ ∘ 𝑥) ∘ ◡𝑔):𝐵–1-1-onto→𝐷)
14	13	ex 418	. . . . . 6 ⊢ ((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) → (𝑥:𝐴–1-1-onto→𝐶 → ((ℎ ∘ 𝑥) ∘ ◡𝑔):𝐵–1-1-onto→𝐷))
15		vex 3454	. . . . . . 7 ⊢ 𝑥 ∈ V
16		f1oeq1 6813	. . . . . . 7 ⊢ (𝑓 = 𝑥 → (𝑓:𝐴–1-1-onto→𝐶 ↔ 𝑥:𝐴–1-1-onto→𝐶))
17	15, 16	elab 3632	. . . . . 6 ⊢ (𝑥 ∈ {𝑓 ∣ 𝑓:𝐴–1-1-onto→𝐶} ↔ 𝑥:𝐴–1-1-onto→𝐶)
18		vex 3454	. . . . . . . . 9 ⊢ ℎ ∈ V
19	18, 15	coex 7943	. . . . . . . 8 ⊢ (ℎ ∘ 𝑥) ∈ V
20		vex 3454	. . . . . . . . 9 ⊢ 𝑔 ∈ V
21	20	cnvex 7938	. . . . . . . 8 ⊢ ◡𝑔 ∈ V
22	19, 21	coex 7943	. . . . . . 7 ⊢ ((ℎ ∘ 𝑥) ∘ ◡𝑔) ∈ V
23		f1oeq1 6813	. . . . . . 7 ⊢ (𝑓 = ((ℎ ∘ 𝑥) ∘ ◡𝑔) → (𝑓:𝐵–1-1-onto→𝐷 ↔ ((ℎ ∘ 𝑥) ∘ ◡𝑔):𝐵–1-1-onto→𝐷))
24	22, 23	elab 3632	. . . . . 6 ⊢ (((ℎ ∘ 𝑥) ∘ ◡𝑔) ∈ {𝑓 ∣ 𝑓:𝐵–1-1-onto→𝐷} ↔ ((ℎ ∘ 𝑥) ∘ ◡𝑔):𝐵–1-1-onto→𝐷)
25	14, 17, 24	3imtr4g 299	. . . . 5 ⊢ ((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) → (𝑥 ∈ {𝑓 ∣ 𝑓:𝐴–1-1-onto→𝐶} → ((ℎ ∘ 𝑥) ∘ ◡𝑔) ∈ {𝑓 ∣ 𝑓:𝐵–1-1-onto→𝐷}))
26		f1ocnv 6838	. . . . . . . . 9 ⊢ (ℎ:𝐶–1-1-onto→𝐷 → ◡ℎ:𝐷–1-1-onto→𝐶)
27	26	ad2antlr 740	. . . . . . . 8 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ 𝑦:𝐵–1-1-onto→𝐷) → ◡ℎ:𝐷–1-1-onto→𝐶)
28		f1oco 6849	. . . . . . . . . 10 ⊢ ((𝑦:𝐵–1-1-onto→𝐷 ∧ 𝑔:𝐴–1-1-onto→𝐵) → (𝑦 ∘ 𝑔):𝐴–1-1-onto→𝐷)
29	28	ancoms 464	. . . . . . . . 9 ⊢ ((𝑔:𝐴–1-1-onto→𝐵 ∧ 𝑦:𝐵–1-1-onto→𝐷) → (𝑦 ∘ 𝑔):𝐴–1-1-onto→𝐷)
30	29	adantlr 728	. . . . . . . 8 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ 𝑦:𝐵–1-1-onto→𝐷) → (𝑦 ∘ 𝑔):𝐴–1-1-onto→𝐷)
31		f1oco 6849	. . . . . . . 8 ⊢ ((◡ℎ:𝐷–1-1-onto→𝐶 ∧ (𝑦 ∘ 𝑔):𝐴–1-1-onto→𝐷) → (◡ℎ ∘ (𝑦 ∘ 𝑔)):𝐴–1-1-onto→𝐶)
32	27, 30, 31	syl2anc 596	. . . . . . 7 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ 𝑦:𝐵–1-1-onto→𝐷) → (◡ℎ ∘ (𝑦 ∘ 𝑔)):𝐴–1-1-onto→𝐶)
33	32	ex 418	. . . . . 6 ⊢ ((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) → (𝑦:𝐵–1-1-onto→𝐷 → (◡ℎ ∘ (𝑦 ∘ 𝑔)):𝐴–1-1-onto→𝐶))
34		vex 3454	. . . . . . 7 ⊢ 𝑦 ∈ V
35		f1oeq1 6813	. . . . . . 7 ⊢ (𝑓 = 𝑦 → (𝑓:𝐵–1-1-onto→𝐷 ↔ 𝑦:𝐵–1-1-onto→𝐷))
36	34, 35	elab 3632	. . . . . 6 ⊢ (𝑦 ∈ {𝑓 ∣ 𝑓:𝐵–1-1-onto→𝐷} ↔ 𝑦:𝐵–1-1-onto→𝐷)
37	18	cnvex 7938	. . . . . . . 8 ⊢ ◡ℎ ∈ V
38	34, 20	coex 7943	. . . . . . . 8 ⊢ (𝑦 ∘ 𝑔) ∈ V
39	37, 38	coex 7943	. . . . . . 7 ⊢ (◡ℎ ∘ (𝑦 ∘ 𝑔)) ∈ V
40		f1oeq1 6813	. . . . . . 7 ⊢ (𝑓 = (◡ℎ ∘ (𝑦 ∘ 𝑔)) → (𝑓:𝐴–1-1-onto→𝐶 ↔ (◡ℎ ∘ (𝑦 ∘ 𝑔)):𝐴–1-1-onto→𝐶))
41	39, 40	elab 3632	. . . . . 6 ⊢ ((◡ℎ ∘ (𝑦 ∘ 𝑔)) ∈ {𝑓 ∣ 𝑓:𝐴–1-1-onto→𝐶} ↔ (◡ℎ ∘ (𝑦 ∘ 𝑔)):𝐴–1-1-onto→𝐶)
42	33, 36, 41	3imtr4g 299	. . . . 5 ⊢ ((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) → (𝑦 ∈ {𝑓 ∣ 𝑓:𝐵–1-1-onto→𝐷} → (◡ℎ ∘ (𝑦 ∘ 𝑔)) ∈ {𝑓 ∣ 𝑓:𝐴–1-1-onto→𝐶}))
43	17, 36	anbi12i 640	. . . . . 6 ⊢ ((𝑥 ∈ {𝑓 ∣ 𝑓:𝐴–1-1-onto→𝐶} ∧ 𝑦 ∈ {𝑓 ∣ 𝑓:𝐵–1-1-onto→𝐷}) ↔ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷))
44		coass 6267	. . . . . . . . . . 11 ⊢ (((ℎ ∘ 𝑥) ∘ ◡𝑔) ∘ 𝑔) = ((ℎ ∘ 𝑥) ∘ (◡𝑔 ∘ 𝑔))
45		f1ococnv1 6855	. . . . . . . . . . . . . 14 ⊢ (𝑔:𝐴–1-1-onto→𝐵 → (◡𝑔 ∘ 𝑔) = ( I ↾ 𝐴))
46	45	ad2antrr 739	. . . . . . . . . . . . 13 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → (◡𝑔 ∘ 𝑔) = ( I ↾ 𝐴))
47	46	coeq2d 5839	. . . . . . . . . . . 12 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → ((ℎ ∘ 𝑥) ∘ (◡𝑔 ∘ 𝑔)) = ((ℎ ∘ 𝑥) ∘ ( I ↾ 𝐴)))
48	9	adantrr 730	. . . . . . . . . . . . 13 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → (ℎ ∘ 𝑥):𝐴–1-1-onto→𝐷)
49		f1of 6825	. . . . . . . . . . . . 13 ⊢ ((ℎ ∘ 𝑥):𝐴–1-1-onto→𝐷 → (ℎ ∘ 𝑥):𝐴⟶𝐷)
50		fcoi1 6757	. . . . . . . . . . . . 13 ⊢ ((ℎ ∘ 𝑥):𝐴⟶𝐷 → ((ℎ ∘ 𝑥) ∘ ( I ↾ 𝐴)) = (ℎ ∘ 𝑥))
51	48, 49, 50	3syl 19	. . . . . . . . . . . 12 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → ((ℎ ∘ 𝑥) ∘ ( I ↾ 𝐴)) = (ℎ ∘ 𝑥))
52	47, 51	eqtrd 2795	. . . . . . . . . . 11 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → ((ℎ ∘ 𝑥) ∘ (◡𝑔 ∘ 𝑔)) = (ℎ ∘ 𝑥))
53	44, 52	eqtr2id 2808	. . . . . . . . . 10 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → (ℎ ∘ 𝑥) = (((ℎ ∘ 𝑥) ∘ ◡𝑔) ∘ 𝑔))
54		coass 6267	. . . . . . . . . . 11 ⊢ ((ℎ ∘ ◡ℎ) ∘ (𝑦 ∘ 𝑔)) = (ℎ ∘ (◡ℎ ∘ (𝑦 ∘ 𝑔)))
55		f1ococnv2 6853	. . . . . . . . . . . . . 14 ⊢ (ℎ:𝐶–1-1-onto→𝐷 → (ℎ ∘ ◡ℎ) = ( I ↾ 𝐷))
56	55	ad2antlr 740	. . . . . . . . . . . . 13 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → (ℎ ∘ ◡ℎ) = ( I ↾ 𝐷))
57	56	coeq1d 5838	. . . . . . . . . . . 12 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → ((ℎ ∘ ◡ℎ) ∘ (𝑦 ∘ 𝑔)) = (( I ↾ 𝐷) ∘ (𝑦 ∘ 𝑔)))
58	30	adantrl 729	. . . . . . . . . . . . 13 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → (𝑦 ∘ 𝑔):𝐴–1-1-onto→𝐷)
59		f1of 6825	. . . . . . . . . . . . 13 ⊢ ((𝑦 ∘ 𝑔):𝐴–1-1-onto→𝐷 → (𝑦 ∘ 𝑔):𝐴⟶𝐷)
60		fcoi2 6758	. . . . . . . . . . . . 13 ⊢ ((𝑦 ∘ 𝑔):𝐴⟶𝐷 → (( I ↾ 𝐷) ∘ (𝑦 ∘ 𝑔)) = (𝑦 ∘ 𝑔))
61	58, 59, 60	3syl 19	. . . . . . . . . . . 12 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → (( I ↾ 𝐷) ∘ (𝑦 ∘ 𝑔)) = (𝑦 ∘ 𝑔))
62	57, 61	eqtrd 2795	. . . . . . . . . . 11 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → ((ℎ ∘ ◡ℎ) ∘ (𝑦 ∘ 𝑔)) = (𝑦 ∘ 𝑔))
63	54, 62	eqtr3id 2809	. . . . . . . . . 10 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → (ℎ ∘ (◡ℎ ∘ (𝑦 ∘ 𝑔))) = (𝑦 ∘ 𝑔))
64	53, 63	eqeq12d 2776	. . . . . . . . 9 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → ((ℎ ∘ 𝑥) = (ℎ ∘ (◡ℎ ∘ (𝑦 ∘ 𝑔))) ↔ (((ℎ ∘ 𝑥) ∘ ◡𝑔) ∘ 𝑔) = (𝑦 ∘ 𝑔)))
65		eqcom 2767	. . . . . . . . 9 ⊢ ((((ℎ ∘ 𝑥) ∘ ◡𝑔) ∘ 𝑔) = (𝑦 ∘ 𝑔) ↔ (𝑦 ∘ 𝑔) = (((ℎ ∘ 𝑥) ∘ ◡𝑔) ∘ 𝑔))
66	64, 65	bitrdi 290	. . . . . . . 8 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → ((ℎ ∘ 𝑥) = (ℎ ∘ (◡ℎ ∘ (𝑦 ∘ 𝑔))) ↔ (𝑦 ∘ 𝑔) = (((ℎ ∘ 𝑥) ∘ ◡𝑔) ∘ 𝑔)))
67		f1of1 6824	. . . . . . . . . 10 ⊢ (ℎ:𝐶–1-1-onto→𝐷 → ℎ:𝐶–1-1→𝐷)
68	67	ad2antlr 740	. . . . . . . . 9 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → ℎ:𝐶–1-1→𝐷)
69		f1of 6825	. . . . . . . . . 10 ⊢ (𝑥:𝐴–1-1-onto→𝐶 → 𝑥:𝐴⟶𝐶)
70	69	ad2antrl 741	. . . . . . . . 9 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → 𝑥:𝐴⟶𝐶)
71	32	adantrl 729	. . . . . . . . . 10 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → (◡ℎ ∘ (𝑦 ∘ 𝑔)):𝐴–1-1-onto→𝐶)
72		f1of 6825	. . . . . . . . . 10 ⊢ ((◡ℎ ∘ (𝑦 ∘ 𝑔)):𝐴–1-1-onto→𝐶 → (◡ℎ ∘ (𝑦 ∘ 𝑔)):𝐴⟶𝐶)
73	71, 72	syl 18	. . . . . . . . 9 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → (◡ℎ ∘ (𝑦 ∘ 𝑔)):𝐴⟶𝐶)
74		cocan1 7300	. . . . . . . . 9 ⊢ ((ℎ:𝐶–1-1→𝐷 ∧ 𝑥:𝐴⟶𝐶 ∧ (◡ℎ ∘ (𝑦 ∘ 𝑔)):𝐴⟶𝐶) → ((ℎ ∘ 𝑥) = (ℎ ∘ (◡ℎ ∘ (𝑦 ∘ 𝑔))) ↔ 𝑥 = (◡ℎ ∘ (𝑦 ∘ 𝑔))))
75	68, 70, 73, 74	syl3anc 1398	. . . . . . . 8 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → ((ℎ ∘ 𝑥) = (ℎ ∘ (◡ℎ ∘ (𝑦 ∘ 𝑔))) ↔ 𝑥 = (◡ℎ ∘ (𝑦 ∘ 𝑔))))
76		f1ofo 6833	. . . . . . . . . 10 ⊢ (𝑔:𝐴–1-1-onto→𝐵 → 𝑔:𝐴–onto→𝐵)
77	76	ad2antrr 739	. . . . . . . . 9 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → 𝑔:𝐴–onto→𝐵)
78		f1ofn 6826	. . . . . . . . . 10 ⊢ (𝑦:𝐵–1-1-onto→𝐷 → 𝑦 Fn 𝐵)
79	78	ad2antll 742	. . . . . . . . 9 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → 𝑦 Fn 𝐵)
80	13	adantrr 730	. . . . . . . . . 10 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → ((ℎ ∘ 𝑥) ∘ ◡𝑔):𝐵–1-1-onto→𝐷)
81		f1ofn 6826	. . . . . . . . . 10 ⊢ (((ℎ ∘ 𝑥) ∘ ◡𝑔):𝐵–1-1-onto→𝐷 → ((ℎ ∘ 𝑥) ∘ ◡𝑔) Fn 𝐵)
82	80, 81	syl 18	. . . . . . . . 9 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → ((ℎ ∘ 𝑥) ∘ ◡𝑔) Fn 𝐵)
83		cocan2 7301	. . . . . . . . 9 ⊢ ((𝑔:𝐴–onto→𝐵 ∧ 𝑦 Fn 𝐵 ∧ ((ℎ ∘ 𝑥) ∘ ◡𝑔) Fn 𝐵) → ((𝑦 ∘ 𝑔) = (((ℎ ∘ 𝑥) ∘ ◡𝑔) ∘ 𝑔) ↔ 𝑦 = ((ℎ ∘ 𝑥) ∘ ◡𝑔)))
84	77, 79, 82, 83	syl3anc 1398	. . . . . . . 8 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → ((𝑦 ∘ 𝑔) = (((ℎ ∘ 𝑥) ∘ ◡𝑔) ∘ 𝑔) ↔ 𝑦 = ((ℎ ∘ 𝑥) ∘ ◡𝑔)))
85	66, 75, 84	3bitr3d 312	. . . . . . 7 ⊢ (((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) ∧ (𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷)) → (𝑥 = (◡ℎ ∘ (𝑦 ∘ 𝑔)) ↔ 𝑦 = ((ℎ ∘ 𝑥) ∘ ◡𝑔)))
86	85	ex 418	. . . . . 6 ⊢ ((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) → ((𝑥:𝐴–1-1-onto→𝐶 ∧ 𝑦:𝐵–1-1-onto→𝐷) → (𝑥 = (◡ℎ ∘ (𝑦 ∘ 𝑔)) ↔ 𝑦 = ((ℎ ∘ 𝑥) ∘ ◡𝑔))))
87	43, 86	biimtrid 245	. . . . 5 ⊢ ((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) → ((𝑥 ∈ {𝑓 ∣ 𝑓:𝐴–1-1-onto→𝐶} ∧ 𝑦 ∈ {𝑓 ∣ 𝑓:𝐵–1-1-onto→𝐷}) → (𝑥 = (◡ℎ ∘ (𝑦 ∘ 𝑔)) ↔ 𝑦 = ((ℎ ∘ 𝑥) ∘ ◡𝑔))))
88	5, 7, 25, 42, 87	en3d 9020	. . . 4 ⊢ ((𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) → {𝑓 ∣ 𝑓:𝐴–1-1-onto→𝐶} ≈ {𝑓 ∣ 𝑓:𝐵–1-1-onto→𝐷})
89	88	exlimivv 1964	. . 3 ⊢ (∃𝑔∃ℎ(𝑔:𝐴–1-1-onto→𝐵 ∧ ℎ:𝐶–1-1-onto→𝐷) → {𝑓 ∣ 𝑓:𝐴–1-1-onto→𝐶} ≈ {𝑓 ∣ 𝑓:𝐵–1-1-onto→𝐷})
90	3, 89	sylbir 238	. 2 ⊢ ((∃𝑔 𝑔:𝐴–1-1-onto→𝐵 ∧ ∃ℎ ℎ:𝐶–1-1-onto→𝐷) → {𝑓 ∣ 𝑓:𝐴–1-1-onto→𝐶} ≈ {𝑓 ∣ 𝑓:𝐵–1-1-onto→𝐷})
91	1, 2, 90	syl2anb 610	1 ⊢ ((𝐴 ≈ 𝐵 ∧ 𝐶 ≈ 𝐷) → {𝑓 ∣ 𝑓:𝐴–1-1-onto→𝐶} ≈ {𝑓 ∣ 𝑓:𝐵–1-1-onto→𝐷})

This proof depends on syntax axioms:   → wi 4   ↔ wb 209   ∧ wa 401   = wceq 1569  ∃wex 1811   ∈ wcel 2144  {cab 2738  Vcvv 3450   class class class wbr 5102   I cid 5544  ^◡ccnv 5649   ↾ cres 5652   ∘ ccom 5654   Fn wfn 6534  ⟶wf 6535  –1-1→wf1 6536  –onto→wfo 6537  –1-1-onto→wf1o 6538   ≈ cen 8974

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1827  ax-4 1841  ax-5 1942  ax-6 1999  ax-7 2040  ax-8 2146  ax-9 2154  ax-10 2177  ax-11 2193  ax-12 2212  ax-ext 2732  ax-sep 5248  ax-nul 5259  ax-pow 5326  ax-pr 5390  ax-un 7752

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1572  df-fal 1582  df-ex 1812  df-nf 1816  df-sb 2099  df-mo 2564  df-eu 2594  df-clab 2739  df-cleq 2752  df-clel 2835  df-nfc 2909  df-ne 2956  df-ral 3077  df-rex 3087  df-rab 3413  df-v 3452  df-sbc 3739  df-csb 3847  df-ss 3896  df-dif 4047  df-in 4091  df-un 4151  df-nul 4279  df-if 4482  df-pw 4558  df-sn 4585  df-pr 4587  df-op 4835  df-uni 4867  df-br 5103  df-opab 5167  df-mpt 5186  df-id 5545  df-xp 5656  df-rel 5657  df-cnv 5658  df-co 5659  df-dm 5660  df-rn 5661  df-res 5662  df-ima 5663  df-iota 6494  df-fun 6541  df-fn 6542  df-f 6543  df-f1 6544  df-fo 6545  df-f1o 6546  df-fv 6547  df-ov 7424  df-oprab 7425  df-mpo 7426  df-map 8853  df-en 8978

This theorem is used by:  poimirlem9  38641