Theorem disjf1o 39378

Description: A bijection built from disjoint sets. (Contributed by Glauco Siliprandi, 17-Aug-2020.)

Hypotheses

Ref	Expression
disjf1o.xph	⊢ Ⅎ𝑥𝜑
disjf1o.f	⊢ 𝐹 = (𝑥 ∈ 𝐴 ↦ 𝐵)
disjf1o.b	⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ 𝑉)
disjf1o.dj	⊢ (𝜑 → Disj 𝑥 ∈ 𝐴 𝐵)
disjf1o.d	⊢ 𝐶 = {𝑥 ∈ 𝐴 ∣ 𝐵 ≠ ∅}
disjf1o.e	⊢ 𝐷 = (ran 𝐹 ∖ {∅})

Assertion

Ref	Expression
disjf1o	⊢ (𝜑 → (𝐹 ↾ 𝐶):𝐶–1-1-onto→𝐷)

Distinct variable groups:   𝑥,𝐴   𝑥,𝐶   𝑥,𝐷   𝑥,𝑉

Allowed substitution hints:   𝜑(𝑥)   𝐵(𝑥)   𝐹(𝑥)

Proof of Theorem disjf1o

Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		disjf1o.xph	. . . 4 ⊢ Ⅎ𝑥𝜑
2		eqid 2622	. . . 4 ⊢ (𝑥 ∈ 𝐶 ↦ 𝐵) = (𝑥 ∈ 𝐶 ↦ 𝐵)
3		simpl 473	. . . . 5 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐶) → 𝜑)
4		disjf1o.d	. . . . . . . 8 ⊢ 𝐶 = {𝑥 ∈ 𝐴 ∣ 𝐵 ≠ ∅}
5		ssrab2 3687	. . . . . . . 8 ⊢ {𝑥 ∈ 𝐴 ∣ 𝐵 ≠ ∅} ⊆ 𝐴
6	4, 5	eqsstri 3635	. . . . . . 7 ⊢ 𝐶 ⊆ 𝐴
7		id 22	. . . . . . 7 ⊢ (𝑥 ∈ 𝐶 → 𝑥 ∈ 𝐶)
8	6, 7	sseldi 3601	. . . . . 6 ⊢ (𝑥 ∈ 𝐶 → 𝑥 ∈ 𝐴)
9	8	adantl 482	. . . . 5 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐶) → 𝑥 ∈ 𝐴)
10		disjf1o.b	. . . . 5 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ 𝑉)
11	3, 9, 10	syl2anc 693	. . . 4 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐶) → 𝐵 ∈ 𝑉)
12	7, 4	syl6eleq 2711	. . . . . . 7 ⊢ (𝑥 ∈ 𝐶 → 𝑥 ∈ {𝑥 ∈ 𝐴 ∣ 𝐵 ≠ ∅})
13		rabid 3116	. . . . . . . 8 ⊢ (𝑥 ∈ {𝑥 ∈ 𝐴 ∣ 𝐵 ≠ ∅} ↔ (𝑥 ∈ 𝐴 ∧ 𝐵 ≠ ∅))
14	13	a1i 11	. . . . . . 7 ⊢ (𝑥 ∈ 𝐶 → (𝑥 ∈ {𝑥 ∈ 𝐴 ∣ 𝐵 ≠ ∅} ↔ (𝑥 ∈ 𝐴 ∧ 𝐵 ≠ ∅)))
15	12, 14	mpbid 222	. . . . . 6 ⊢ (𝑥 ∈ 𝐶 → (𝑥 ∈ 𝐴 ∧ 𝐵 ≠ ∅))
16	15	simprd 479	. . . . 5 ⊢ (𝑥 ∈ 𝐶 → 𝐵 ≠ ∅)
17	16	adantl 482	. . . 4 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐶) → 𝐵 ≠ ∅)
18	6	a1i 11	. . . . 5 ⊢ (𝜑 → 𝐶 ⊆ 𝐴)
19		disjf1o.dj	. . . . 5 ⊢ (𝜑 → Disj 𝑥 ∈ 𝐴 𝐵)
20		disjss1 4626	. . . . 5 ⊢ (𝐶 ⊆ 𝐴 → (Disj 𝑥 ∈ 𝐴 𝐵 → Disj 𝑥 ∈ 𝐶 𝐵))
21	18, 19, 20	sylc 65	. . . 4 ⊢ (𝜑 → Disj 𝑥 ∈ 𝐶 𝐵)
22	1, 2, 11, 17, 21	disjf1 39369	. . 3 ⊢ (𝜑 → (𝑥 ∈ 𝐶 ↦ 𝐵):𝐶–1-1→𝑉)
23		f1f1orn 6148	. . 3 ⊢ ((𝑥 ∈ 𝐶 ↦ 𝐵):𝐶–1-1→𝑉 → (𝑥 ∈ 𝐶 ↦ 𝐵):𝐶–1-1-onto→ran (𝑥 ∈ 𝐶 ↦ 𝐵))
24	22, 23	syl 17	. 2 ⊢ (𝜑 → (𝑥 ∈ 𝐶 ↦ 𝐵):𝐶–1-1-onto→ran (𝑥 ∈ 𝐶 ↦ 𝐵))
25		disjf1o.f	. . . . . 6 ⊢ 𝐹 = (𝑥 ∈ 𝐴 ↦ 𝐵)
26	25	a1i 11	. . . . 5 ⊢ (𝜑 → 𝐹 = (𝑥 ∈ 𝐴 ↦ 𝐵))
27	26	reseq1d 5395	. . . 4 ⊢ (𝜑 → (𝐹 ↾ 𝐶) = ((𝑥 ∈ 𝐴 ↦ 𝐵) ↾ 𝐶))
28	18	resmptd 5452	. . . 4 ⊢ (𝜑 → ((𝑥 ∈ 𝐴 ↦ 𝐵) ↾ 𝐶) = (𝑥 ∈ 𝐶 ↦ 𝐵))
29	27, 28	eqtrd 2656	. . 3 ⊢ (𝜑 → (𝐹 ↾ 𝐶) = (𝑥 ∈ 𝐶 ↦ 𝐵))
30		eqidd 2623	. . 3 ⊢ (𝜑 → 𝐶 = 𝐶)
31		simpl 473	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐷) → 𝜑)
32		id 22	. . . . . . . . . 10 ⊢ (𝑦 ∈ 𝐷 → 𝑦 ∈ 𝐷)
33		disjf1o.e	. . . . . . . . . 10 ⊢ 𝐷 = (ran 𝐹 ∖ {∅})
34	32, 33	syl6eleq 2711	. . . . . . . . 9 ⊢ (𝑦 ∈ 𝐷 → 𝑦 ∈ (ran 𝐹 ∖ {∅}))
35		eldifsni 4320	. . . . . . . . 9 ⊢ (𝑦 ∈ (ran 𝐹 ∖ {∅}) → 𝑦 ≠ ∅)
36	34, 35	syl 17	. . . . . . . 8 ⊢ (𝑦 ∈ 𝐷 → 𝑦 ≠ ∅)
37	36	adantl 482	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐷) → 𝑦 ≠ ∅)
38		eldifi 3732	. . . . . . . . . 10 ⊢ (𝑦 ∈ (ran 𝐹 ∖ {∅}) → 𝑦 ∈ ran 𝐹)
39	34, 38	syl 17	. . . . . . . . 9 ⊢ (𝑦 ∈ 𝐷 → 𝑦 ∈ ran 𝐹)
40	25	elrnmpt 5372	. . . . . . . . . 10 ⊢ (𝑦 ∈ ran 𝐹 → (𝑦 ∈ ran 𝐹 ↔ ∃𝑥 ∈ 𝐴 𝑦 = 𝐵))
41	39, 40	syl 17	. . . . . . . . 9 ⊢ (𝑦 ∈ 𝐷 → (𝑦 ∈ ran 𝐹 ↔ ∃𝑥 ∈ 𝐴 𝑦 = 𝐵))
42	39, 41	mpbid 222	. . . . . . . 8 ⊢ (𝑦 ∈ 𝐷 → ∃𝑥 ∈ 𝐴 𝑦 = 𝐵)
43	42	adantl 482	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐷) → ∃𝑥 ∈ 𝐴 𝑦 = 𝐵)
44		nfv 1843	. . . . . . . . . 10 ⊢ Ⅎ𝑥 𝑦 ≠ ∅
45	1, 44	nfan 1828	. . . . . . . . 9 ⊢ Ⅎ𝑥(𝜑 ∧ 𝑦 ≠ ∅)
46		nfcv 2764	. . . . . . . . . 10 ⊢ Ⅎ𝑥𝑦
47		nfmpt1 4747	. . . . . . . . . . 11 ⊢ Ⅎ𝑥(𝑥 ∈ 𝐶 ↦ 𝐵)
48	47	nfrn 5368	. . . . . . . . . 10 ⊢ Ⅎ𝑥ran (𝑥 ∈ 𝐶 ↦ 𝐵)
49	46, 48	nfel 2777	. . . . . . . . 9 ⊢ Ⅎ𝑥 𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵)
50		simp3 1063	. . . . . . . . . . . 12 ⊢ ((𝑦 ≠ ∅ ∧ 𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝑦 = 𝐵)
51		simp2 1062	. . . . . . . . . . . . . . . 16 ⊢ ((𝑦 ≠ ∅ ∧ 𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝑥 ∈ 𝐴)
52		id 22	. . . . . . . . . . . . . . . . . . . 20 ⊢ (𝑦 = 𝐵 → 𝑦 = 𝐵)
53	52	eqcomd 2628	. . . . . . . . . . . . . . . . . . 19 ⊢ (𝑦 = 𝐵 → 𝐵 = 𝑦)
54	53	adantl 482	. . . . . . . . . . . . . . . . . 18 ⊢ ((𝑦 ≠ ∅ ∧ 𝑦 = 𝐵) → 𝐵 = 𝑦)
55		simpl 473	. . . . . . . . . . . . . . . . . 18 ⊢ ((𝑦 ≠ ∅ ∧ 𝑦 = 𝐵) → 𝑦 ≠ ∅)
56	54, 55	eqnetrd 2861	. . . . . . . . . . . . . . . . 17 ⊢ ((𝑦 ≠ ∅ ∧ 𝑦 = 𝐵) → 𝐵 ≠ ∅)
57	56	3adant2 1080	. . . . . . . . . . . . . . . 16 ⊢ ((𝑦 ≠ ∅ ∧ 𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝐵 ≠ ∅)
58	51, 57	jca 554	. . . . . . . . . . . . . . 15 ⊢ ((𝑦 ≠ ∅ ∧ 𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → (𝑥 ∈ 𝐴 ∧ 𝐵 ≠ ∅))
59	58, 13	sylibr 224	. . . . . . . . . . . . . 14 ⊢ ((𝑦 ≠ ∅ ∧ 𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝑥 ∈ {𝑥 ∈ 𝐴 ∣ 𝐵 ≠ ∅})
60	4	eqcomi 2631	. . . . . . . . . . . . . . 15 ⊢ {𝑥 ∈ 𝐴 ∣ 𝐵 ≠ ∅} = 𝐶
61	60	a1i 11	. . . . . . . . . . . . . 14 ⊢ ((𝑦 ≠ ∅ ∧ 𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → {𝑥 ∈ 𝐴 ∣ 𝐵 ≠ ∅} = 𝐶)
62	59, 61	eleqtrd 2703	. . . . . . . . . . . . 13 ⊢ ((𝑦 ≠ ∅ ∧ 𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝑥 ∈ 𝐶)
63		eqvisset 3211	. . . . . . . . . . . . . 14 ⊢ (𝑦 = 𝐵 → 𝐵 ∈ V)
64	63	3ad2ant3 1084	. . . . . . . . . . . . 13 ⊢ ((𝑦 ≠ ∅ ∧ 𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝐵 ∈ V)
65	2	elrnmpt1 5374	. . . . . . . . . . . . 13 ⊢ ((𝑥 ∈ 𝐶 ∧ 𝐵 ∈ V) → 𝐵 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵))
66	62, 64, 65	syl2anc 693	. . . . . . . . . . . 12 ⊢ ((𝑦 ≠ ∅ ∧ 𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝐵 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵))
67	50, 66	eqeltrd 2701	. . . . . . . . . . 11 ⊢ ((𝑦 ≠ ∅ ∧ 𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵))
68	67	3adant1l 1318	. . . . . . . . . 10 ⊢ (((𝜑 ∧ 𝑦 ≠ ∅) ∧ 𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵))
69	68	3exp 1264	. . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑦 ≠ ∅) → (𝑥 ∈ 𝐴 → (𝑦 = 𝐵 → 𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵))))
70	45, 49, 69	rexlimd 3026	. . . . . . . 8 ⊢ ((𝜑 ∧ 𝑦 ≠ ∅) → (∃𝑥 ∈ 𝐴 𝑦 = 𝐵 → 𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵)))
71	70	imp 445	. . . . . . 7 ⊢ (((𝜑 ∧ 𝑦 ≠ ∅) ∧ ∃𝑥 ∈ 𝐴 𝑦 = 𝐵) → 𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵))
72	31, 37, 43, 71	syl21anc 1325	. . . . . 6 ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐷) → 𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵))
73	72	ralrimiva 2966	. . . . 5 ⊢ (𝜑 → ∀𝑦 ∈ 𝐷 𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵))
74		dfss3 3592	. . . . 5 ⊢ (𝐷 ⊆ ran (𝑥 ∈ 𝐶 ↦ 𝐵) ↔ ∀𝑦 ∈ 𝐷 𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵))
75	73, 74	sylibr 224	. . . 4 ⊢ (𝜑 → 𝐷 ⊆ ran (𝑥 ∈ 𝐶 ↦ 𝐵))
76		simpl 473	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵)) → 𝜑)
77		vex 3203	. . . . . . . . . 10 ⊢ 𝑦 ∈ V
78	2	elrnmpt 5372	. . . . . . . . . 10 ⊢ (𝑦 ∈ V → (𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵) ↔ ∃𝑥 ∈ 𝐶 𝑦 = 𝐵))
79	77, 78	ax-mp 5	. . . . . . . . 9 ⊢ (𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵) ↔ ∃𝑥 ∈ 𝐶 𝑦 = 𝐵)
80	79	biimpi 206	. . . . . . . 8 ⊢ (𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵) → ∃𝑥 ∈ 𝐶 𝑦 = 𝐵)
81	80	adantl 482	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵)) → ∃𝑥 ∈ 𝐶 𝑦 = 𝐵)
82		nfv 1843	. . . . . . . . 9 ⊢ Ⅎ𝑥 𝑦 ∈ 𝐷
83		simpr 477	. . . . . . . . . . . . . 14 ⊢ ((𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵) → 𝑦 = 𝐵)
84	8	adantr 481	. . . . . . . . . . . . . . 15 ⊢ ((𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵) → 𝑥 ∈ 𝐴)
85	83, 63	syl 17	. . . . . . . . . . . . . . 15 ⊢ ((𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵) → 𝐵 ∈ V)
86	25	elrnmpt1 5374	. . . . . . . . . . . . . . 15 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝐵 ∈ V) → 𝐵 ∈ ran 𝐹)
87	84, 85, 86	syl2anc 693	. . . . . . . . . . . . . 14 ⊢ ((𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵) → 𝐵 ∈ ran 𝐹)
88	83, 87	eqeltrd 2701	. . . . . . . . . . . . 13 ⊢ ((𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵) → 𝑦 ∈ ran 𝐹)
89	88	3adant1 1079	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵) → 𝑦 ∈ ran 𝐹)
90	16	adantr 481	. . . . . . . . . . . . . . 15 ⊢ ((𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵) → 𝐵 ≠ ∅)
91	83, 90	eqnetrd 2861	. . . . . . . . . . . . . 14 ⊢ ((𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵) → 𝑦 ≠ ∅)
92		nelsn 4212	. . . . . . . . . . . . . 14 ⊢ (𝑦 ≠ ∅ → ¬ 𝑦 ∈ {∅})
93	91, 92	syl 17	. . . . . . . . . . . . 13 ⊢ ((𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵) → ¬ 𝑦 ∈ {∅})
94	93	3adant1 1079	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵) → ¬ 𝑦 ∈ {∅})
95	89, 94	eldifd 3585	. . . . . . . . . . 11 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵) → 𝑦 ∈ (ran 𝐹 ∖ {∅}))
96	95, 33	syl6eleqr 2712	. . . . . . . . . 10 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵) → 𝑦 ∈ 𝐷)
97	96	3exp 1264	. . . . . . . . 9 ⊢ (𝜑 → (𝑥 ∈ 𝐶 → (𝑦 = 𝐵 → 𝑦 ∈ 𝐷)))
98	1, 82, 97	rexlimd 3026	. . . . . . . 8 ⊢ (𝜑 → (∃𝑥 ∈ 𝐶 𝑦 = 𝐵 → 𝑦 ∈ 𝐷))
99	98	imp 445	. . . . . . 7 ⊢ ((𝜑 ∧ ∃𝑥 ∈ 𝐶 𝑦 = 𝐵) → 𝑦 ∈ 𝐷)
100	76, 81, 99	syl2anc 693	. . . . . 6 ⊢ ((𝜑 ∧ 𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵)) → 𝑦 ∈ 𝐷)
101	100	ralrimiva 2966	. . . . 5 ⊢ (𝜑 → ∀𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵)𝑦 ∈ 𝐷)
102		dfss3 3592	. . . . 5 ⊢ (ran (𝑥 ∈ 𝐶 ↦ 𝐵) ⊆ 𝐷 ↔ ∀𝑦 ∈ ran (𝑥 ∈ 𝐶 ↦ 𝐵)𝑦 ∈ 𝐷)
103	101, 102	sylibr 224	. . . 4 ⊢ (𝜑 → ran (𝑥 ∈ 𝐶 ↦ 𝐵) ⊆ 𝐷)
104	75, 103	eqssd 3620	. . 3 ⊢ (𝜑 → 𝐷 = ran (𝑥 ∈ 𝐶 ↦ 𝐵))
105	29, 30, 104	f1oeq123d 6133	. 2 ⊢ (𝜑 → ((𝐹 ↾ 𝐶):𝐶–1-1-onto→𝐷 ↔ (𝑥 ∈ 𝐶 ↦ 𝐵):𝐶–1-1-onto→ran (𝑥 ∈ 𝐶 ↦ 𝐵)))
106	24, 105	mpbird 247	1 ⊢ (𝜑 → (𝐹 ↾ 𝐶):𝐶–1-1-onto→𝐷)

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 196   ∧ wa 384   ∧ w3a 1037   = wceq 1483  Ⅎwnf 1708   ∈ wcel 1990   ≠ wne 2794  ∀wral 2912  ∃wrex 2913  {crab 2916  Vcvv 3200   ∖ cdif 3571   ⊆ wss 3574  ∅c0 3915  {csn 4177  Disj wdisj 4620   ↦ cmpt 4729  ran crn 5115   ↾ cres 5116  –1-1→wf1 5885  –1-1-onto→wf1o 5887

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-8 1992  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-sep 4781  ax-nul 4789  ax-pow 4843  ax-pr 4906

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-eu 2474  df-mo 2475  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ne 2795  df-ral 2917  df-rex 2918  df-reu 2919  df-rmo 2920  df-rab 2921  df-v 3202  df-sbc 3436  df-csb 3534  df-dif 3577  df-un 3579  df-in 3581  df-ss 3588  df-nul 3916  df-if 4087  df-sn 4178  df-pr 4180  df-op 4184  df-uni 4437  df-disj 4621  df-br 4654  df-opab 4713  df-mpt 4730  df-id 5024  df-xp 5120  df-rel 5121  df-cnv 5122  df-co 5123  df-dm 5124  df-rn 5125  df-res 5126  df-ima 5127  df-iota 5851  df-fun 5890  df-fn 5891  df-f 5892  df-f1 5893  df-fo 5894  df-f1o 5895  df-fv 5896

This theorem is referenced by:  sge0fodjrnlem  40633