Theorem choicefi 46213

Description: For a finite set, a choice function exists, without using the axiom of choice. (Contributed by Glauco Siliprandi, 24-Dec-2020.)

Hypotheses

Ref	Expression
choicefi.a	⊢ (𝜑 → 𝐴 ∈ Fin)
choicefi.b	⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ 𝑊)
choicefi.n	⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ≠ ∅)

Assertion

Ref	Expression
choicefi	⊢ (𝜑 → ∃𝑓(𝑓 Fn 𝐴 ∧ ∀𝑥 ∈ 𝐴 (𝑓‘𝑥) ∈ 𝐵))

Distinct variable groups:   𝐴,𝑓,𝑥   𝐵,𝑓   𝜑,𝑥

Allowed substitution hints:   𝜑(𝑓)   𝐵(𝑥)   𝑊(𝑥, 𝑓)

Proof of Theorem choicefi

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

Step	Hyp	Ref	Expression
1		choicefi.a	. . 3 ⊢ (𝜑 → 𝐴 ∈ Fin)
2		mptfi 9340	. . 3 ⊢ (𝐴 ∈ Fin → (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ Fin)
3		rnfi 9329	. . 3 ⊢ ((𝑥 ∈ 𝐴 ↦ 𝐵) ∈ Fin → ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ Fin)
4		fnchoice 46045	. . 3 ⊢ (ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ Fin → ∃𝑔(𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦)))
5	1, 2, 3, 4	4syl 20	. 2 ⊢ (𝜑 → ∃𝑔(𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦)))
6		simpl 488	. . . . 5 ⊢ ((𝜑 ∧ (𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦))) → 𝜑)
7		simprl 783	. . . . 5 ⊢ ((𝜑 ∧ (𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦))) → 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵))
8		nfv 1947	. . . . . . . 8 ⊢ Ⅎ𝑦𝜑
9		nfra1 3287	. . . . . . . 8 ⊢ Ⅎ𝑦∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦)
10	8, 9	nfan 1932	. . . . . . 7 ⊢ Ⅎ𝑦(𝜑 ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦))
11		rspa 3252	. . . . . . . . . . . 12 ⊢ ((∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦) ∧ 𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)) → (𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦))
12	11	adantll 727	. . . . . . . . . . 11 ⊢ (((𝜑 ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦)) ∧ 𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)) → (𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦))
13		vex 3455	. . . . . . . . . . . . . . 15 ⊢ 𝑦 ∈ V
14		eqid 2761	. . . . . . . . . . . . . . . 16 ⊢ (𝑥 ∈ 𝐴 ↦ 𝐵) = (𝑥 ∈ 𝐴 ↦ 𝐵)
15	14	elrnmpt 5940	. . . . . . . . . . . . . . 15 ⊢ (𝑦 ∈ V → (𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵) ↔ ∃𝑥 ∈ 𝐴 𝑦 = 𝐵))
16	13, 15	ax-mp 5	. . . . . . . . . . . . . 14 ⊢ (𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵) ↔ ∃𝑥 ∈ 𝐴 𝑦 = 𝐵)
17	16	bilani 510	. . . . . . . . . . . . 13 ⊢ ((𝜑 ∧ 𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)) → ∃𝑥 ∈ 𝐴 𝑦 = 𝐵)
18		simp3 1156	. . . . . . . . . . . . . . . . 17 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝑦 = 𝐵)
19		choicefi.n	. . . . . . . . . . . . . . . . . 18 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ≠ ∅)
20	19	3adant3 1150	. . . . . . . . . . . . . . . . 17 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝐵 ≠ ∅)
21	18, 20	eqnetrd 3023	. . . . . . . . . . . . . . . 16 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝑦 ≠ ∅)
22	21	3exp 1137	. . . . . . . . . . . . . . 15 ⊢ (𝜑 → (𝑥 ∈ 𝐴 → (𝑦 = 𝐵 → 𝑦 ≠ ∅)))
23	22	rexlimdv 3162	. . . . . . . . . . . . . 14 ⊢ (𝜑 → (∃𝑥 ∈ 𝐴 𝑦 = 𝐵 → 𝑦 ≠ ∅))
24	23	adantr 486	. . . . . . . . . . . . 13 ⊢ ((𝜑 ∧ 𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)) → (∃𝑥 ∈ 𝐴 𝑦 = 𝐵 → 𝑦 ≠ ∅))
25	17, 24	mpd 16	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)) → 𝑦 ≠ ∅)
26	25	adantlr 728	. . . . . . . . . . 11 ⊢ (((𝜑 ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦)) ∧ 𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)) → 𝑦 ≠ ∅)
27		id 23	. . . . . . . . . . . 12 ⊢ ((𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦) → (𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦))
28	27	imp 412	. . . . . . . . . . 11 ⊢ (((𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦) ∧ 𝑦 ≠ ∅) → (𝑔‘𝑦) ∈ 𝑦)
29	12, 26, 28	syl2anc 596	. . . . . . . . . 10 ⊢ (((𝜑 ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦)) ∧ 𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)) → (𝑔‘𝑦) ∈ 𝑦)
30	29	ex 418	. . . . . . . . 9 ⊢ ((𝜑 ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦)) → (𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵) → (𝑔‘𝑦) ∈ 𝑦))
31	10, 30	ralrimi 3261	. . . . . . . 8 ⊢ ((𝜑 ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦)) → ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦)
32		rsp 3251	. . . . . . . 8 ⊢ (∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦 → (𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵) → (𝑔‘𝑦) ∈ 𝑦))
33	31, 32	syl 18	. . . . . . 7 ⊢ ((𝜑 ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦)) → (𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵) → (𝑔‘𝑦) ∈ 𝑦))
34	10, 33	ralrimi 3261	. . . . . 6 ⊢ ((𝜑 ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦)) → ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦)
35	34	adantrl 729	. . . . 5 ⊢ ((𝜑 ∧ (𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦))) → ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦)
36		vex 3455	. . . . . . . . 9 ⊢ 𝑔 ∈ V
37	36	a1i 11	. . . . . . . 8 ⊢ (𝜑 → 𝑔 ∈ V)
38	1	mptexd 7230	. . . . . . . 8 ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ V)
39		coexg 7941	. . . . . . . 8 ⊢ ((𝑔 ∈ V ∧ (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ V) → (𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) ∈ V)
40	37, 38, 39	syl2anc 596	. . . . . . 7 ⊢ (𝜑 → (𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) ∈ V)
41	40	3ad2ant1 1151	. . . . . 6 ⊢ ((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦) → (𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) ∈ V)
42		simpr 490	. . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵)) → 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵))
43		choicefi.b	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ 𝑊)
44	43	ralrimiva 3155	. . . . . . . . . . 11 ⊢ (𝜑 → ∀𝑥 ∈ 𝐴 𝐵 ∈ 𝑊)
45	14	fnmpt 6679	. . . . . . . . . . 11 ⊢ (∀𝑥 ∈ 𝐴 𝐵 ∈ 𝑊 → (𝑥 ∈ 𝐴 ↦ 𝐵) Fn 𝐴)
46	44, 45	syl 18	. . . . . . . . . 10 ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐵) Fn 𝐴)
47	46	adantr 486	. . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵)) → (𝑥 ∈ 𝐴 ↦ 𝐵) Fn 𝐴)
48		ssidd 3954	. . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵)) → ran (𝑥 ∈ 𝐴 ↦ 𝐵) ⊆ ran (𝑥 ∈ 𝐴 ↦ 𝐵))
49		fnco 6657	. . . . . . . . 9 ⊢ ((𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ (𝑥 ∈ 𝐴 ↦ 𝐵) Fn 𝐴 ∧ ran (𝑥 ∈ 𝐴 ↦ 𝐵) ⊆ ran (𝑥 ∈ 𝐴 ↦ 𝐵)) → (𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) Fn 𝐴)
50	42, 47, 48, 49	syl3anc 1398	. . . . . . . 8 ⊢ ((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵)) → (𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) Fn 𝐴)
51	50	3adant3 1150	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦) → (𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) Fn 𝐴)
52		nfv 1947	. . . . . . . . 9 ⊢ Ⅎ𝑥𝜑
53		nfcv 2923	. . . . . . . . . 10 ⊢ Ⅎ𝑥𝑔
54		nfmpt1 5204	. . . . . . . . . . 11 ⊢ Ⅎ𝑥(𝑥 ∈ 𝐴 ↦ 𝐵)
55	54	nfrn 5934	. . . . . . . . . 10 ⊢ Ⅎ𝑥ran (𝑥 ∈ 𝐴 ↦ 𝐵)
56	53, 55	nffn 6638	. . . . . . . . 9 ⊢ Ⅎ𝑥 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵)
57		nfv 1947	. . . . . . . . . 10 ⊢ Ⅎ𝑥(𝑔‘𝑦) ∈ 𝑦
58	55, 57	nfralw 3310	. . . . . . . . 9 ⊢ Ⅎ𝑥∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦
59	52, 56, 58	nf3an 1934	. . . . . . . 8 ⊢ Ⅎ𝑥(𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦)
60		funmpt 6578	. . . . . . . . . . . . . 14 ⊢ Fun (𝑥 ∈ 𝐴 ↦ 𝐵)
61	60	a1i 11	. . . . . . . . . . . . 13 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → Fun (𝑥 ∈ 𝐴 ↦ 𝐵))
62		simpr 490	. . . . . . . . . . . . . 14 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ 𝐴)
63	14, 43	dmmptd 6684	. . . . . . . . . . . . . . . 16 ⊢ (𝜑 → dom (𝑥 ∈ 𝐴 ↦ 𝐵) = 𝐴)
64	63	eqcomd 2767	. . . . . . . . . . . . . . 15 ⊢ (𝜑 → 𝐴 = dom (𝑥 ∈ 𝐴 ↦ 𝐵))
65	64	adantr 486	. . . . . . . . . . . . . 14 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐴 = dom (𝑥 ∈ 𝐴 ↦ 𝐵))
66	62, 65	eleqtrd 2863	. . . . . . . . . . . . 13 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ dom (𝑥 ∈ 𝐴 ↦ 𝐵))
67		fvco 6983	. . . . . . . . . . . . 13 ⊢ ((Fun (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ 𝑥 ∈ dom (𝑥 ∈ 𝐴 ↦ 𝐵)) → ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))‘𝑥) = (𝑔‘((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥)))
68	61, 66, 67	syl2anc 596	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))‘𝑥) = (𝑔‘((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥)))
69	14	fvmpt2 7005	. . . . . . . . . . . . . 14 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝐵 ∈ 𝑊) → ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) = 𝐵)
70	62, 43, 69	syl2anc 596	. . . . . . . . . . . . 13 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) = 𝐵)
71	70	fveq2d 6889	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (𝑔‘((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥)) = (𝑔‘𝐵))
72	68, 71	eqtrd 2796	. . . . . . . . . . 11 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))‘𝑥) = (𝑔‘𝐵))
73	72	3ad2antl1 1204	. . . . . . . . . 10 ⊢ (((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦) ∧ 𝑥 ∈ 𝐴) → ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))‘𝑥) = (𝑔‘𝐵))
74	14	elrnmpt1 5942	. . . . . . . . . . . . 13 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝐵 ∈ 𝑊) → 𝐵 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵))
75	62, 43, 74	syl2anc 596	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵))
76	75	3ad2antl1 1204	. . . . . . . . . . 11 ⊢ (((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦) ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵))
77		simpl3 1212	. . . . . . . . . . 11 ⊢ (((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦) ∧ 𝑥 ∈ 𝐴) → ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦)
78		fveq2 6885	. . . . . . . . . . . . 13 ⊢ (𝑦 = 𝐵 → (𝑔‘𝑦) = (𝑔‘𝐵))
79		id 23	. . . . . . . . . . . . 13 ⊢ (𝑦 = 𝐵 → 𝑦 = 𝐵)
80	78, 79	eleq12d 2855	. . . . . . . . . . . 12 ⊢ (𝑦 = 𝐵 → ((𝑔‘𝑦) ∈ 𝑦 ↔ (𝑔‘𝐵) ∈ 𝐵))
81	80	rspcva 3575	. . . . . . . . . . 11 ⊢ ((𝐵 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦) → (𝑔‘𝐵) ∈ 𝐵)
82	76, 77, 81	syl2anc 596	. . . . . . . . . 10 ⊢ (((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦) ∧ 𝑥 ∈ 𝐴) → (𝑔‘𝐵) ∈ 𝐵)
83	73, 82	eqeltrd 2861	. . . . . . . . 9 ⊢ (((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦) ∧ 𝑥 ∈ 𝐴) → ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))‘𝑥) ∈ 𝐵)
84	83	ex 418	. . . . . . . 8 ⊢ ((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦) → (𝑥 ∈ 𝐴 → ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))‘𝑥) ∈ 𝐵))
85	59, 84	ralrimi 3261	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦) → ∀𝑥 ∈ 𝐴 ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))‘𝑥) ∈ 𝐵)
86	51, 85	jca 521	. . . . . 6 ⊢ ((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦) → ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) Fn 𝐴 ∧ ∀𝑥 ∈ 𝐴 ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))‘𝑥) ∈ 𝐵))
87		fneq1 6630	. . . . . . . 8 ⊢ (𝑓 = (𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) → (𝑓 Fn 𝐴 ↔ (𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) Fn 𝐴))
88		nfcv 2923	. . . . . . . . . 10 ⊢ Ⅎ𝑥𝑓
89	53, 54	nfco 5843	. . . . . . . . . 10 ⊢ Ⅎ𝑥(𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))
90	88, 89	nfeq 2936	. . . . . . . . 9 ⊢ Ⅎ𝑥 𝑓 = (𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))
91		fveq1 6884	. . . . . . . . . 10 ⊢ (𝑓 = (𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) → (𝑓‘𝑥) = ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))‘𝑥))
92	91	eleq1d 2846	. . . . . . . . 9 ⊢ (𝑓 = (𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) → ((𝑓‘𝑥) ∈ 𝐵 ↔ ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))‘𝑥) ∈ 𝐵))
93	90, 92	ralbid 3276	. . . . . . . 8 ⊢ (𝑓 = (𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) → (∀𝑥 ∈ 𝐴 (𝑓‘𝑥) ∈ 𝐵 ↔ ∀𝑥 ∈ 𝐴 ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))‘𝑥) ∈ 𝐵))
94	87, 93	anbi12d 644	. . . . . . 7 ⊢ (𝑓 = (𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) → ((𝑓 Fn 𝐴 ∧ ∀𝑥 ∈ 𝐴 (𝑓‘𝑥) ∈ 𝐵) ↔ ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) Fn 𝐴 ∧ ∀𝑥 ∈ 𝐴 ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))‘𝑥) ∈ 𝐵)))
95	94	spcegv 3552	. . . . . 6 ⊢ ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) ∈ V → (((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵)) Fn 𝐴 ∧ ∀𝑥 ∈ 𝐴 ((𝑔 ∘ (𝑥 ∈ 𝐴 ↦ 𝐵))‘𝑥) ∈ 𝐵) → ∃𝑓(𝑓 Fn 𝐴 ∧ ∀𝑥 ∈ 𝐴 (𝑓‘𝑥) ∈ 𝐵)))
96	41, 86, 95	sylc 66	. . . . 5 ⊢ ((𝜑 ∧ 𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑔‘𝑦) ∈ 𝑦) → ∃𝑓(𝑓 Fn 𝐴 ∧ ∀𝑥 ∈ 𝐴 (𝑓‘𝑥) ∈ 𝐵))
97	6, 7, 35, 96	syl3anc 1398	. . . 4 ⊢ ((𝜑 ∧ (𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦))) → ∃𝑓(𝑓 Fn 𝐴 ∧ ∀𝑥 ∈ 𝐴 (𝑓‘𝑥) ∈ 𝐵))
98	97	ex 418	. . 3 ⊢ (𝜑 → ((𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦)) → ∃𝑓(𝑓 Fn 𝐴 ∧ ∀𝑥 ∈ 𝐴 (𝑓‘𝑥) ∈ 𝐵)))
99	98	exlimdv 1966	. 2 ⊢ (𝜑 → (∃𝑔(𝑔 Fn ran (𝑥 ∈ 𝐴 ↦ 𝐵) ∧ ∀𝑦 ∈ ran (𝑥 ∈ 𝐴 ↦ 𝐵)(𝑦 ≠ ∅ → (𝑔‘𝑦) ∈ 𝑦)) → ∃𝑓(𝑓 Fn 𝐴 ∧ ∀𝑥 ∈ 𝐴 (𝑓‘𝑥) ∈ 𝐵)))
100	5, 99	mpd 16	1 ⊢ (𝜑 → ∃𝑓(𝑓 Fn 𝐴 ∧ ∀𝑥 ∈ 𝐴 (𝑓‘𝑥) ∈ 𝐵))

This proof depends on syntax axioms:   → wi 4   ↔ wb 209   ∧ wa 401   ∧ w3a 1103   = wceq 1570  ∃wex 1812   ∈ wcel 2145   ≠ wne 2956  ∀wral 3077  ∃wrex 3087  Vcvv 3451   ⊆ wss 3899  ∅c0 4279   ↦ cmpt 5186  dom cdm 5651  ran crn 5652   ∘ ccom 5655  Fun wfun 6532   Fn wfn 6533  ‘cfv 6538  Fincfn 8973

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2147  ax-9 2155  ax-10 2178  ax-11 2194  ax-12 2213  ax-ext 2733  ax-rep 5232  ax-sep 5249  ax-nul 5260  ax-pow 5327  ax-pr 5391  ax-un 7751

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3or 1104  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2100  df-mo 2565  df-eu 2595  df-clab 2740  df-cleq 2753  df-clel 2836  df-nfc 2910  df-ne 2957  df-ral 3078  df-rex 3088  df-reu 3367  df-rab 3414  df-v 3453  df-sbc 3740  df-csb 3848  df-dif 3902  df-un 3904  df-in 3906  df-ss 3916  df-pss 3919  df-nul 4280  df-if 4483  df-pw 4559  df-sn 4585  df-pr 4587  df-op 4591  df-uni 4868  df-iun 4953  df-br 5104  df-opab 5168  df-mpt 5187  df-tr 5213  df-id 5546  df-eprel 5551  df-po 5559  df-so 5560  df-fr 5604  df-we 5606  df-xp 5657  df-rel 5658  df-cnv 5659  df-co 5660  df-dm 5661  df-rn 5662  df-res 5663  df-ima 5664  df-ord 6365  df-on 6366  df-lim 6367  df-suc 6368  df-iota 6494  df-fun 6540  df-fn 6541  df-f 6542  df-f1 6543  df-fo 6544  df-f1o 6545  df-fv 6546  df-om 7878  df-1st 8001  df-2nd 8002  df-1o 8476  df-en 8974  df-dom 8975  df-fin 8977

This theorem is used by:  axccdom  46234  axccd2  46241  qndenserrnbllem  47303  hoiqssbllem3  47633