Theorem fvelimad 39458

Description: Function value in an image. (Contributed by Glauco Siliprandi, 23-Oct-2021.)

Hypotheses

Ref	Expression
fvelimad.x	⊢ Ⅎ𝑥𝐹
fvelimad.f	⊢ (𝜑 → 𝐹 Fn 𝐴)
fvelimad.c	⊢ (𝜑 → 𝐶 ∈ (𝐹 “ 𝐵))

Assertion

Ref	Expression
fvelimad	⊢ (𝜑 → ∃𝑥 ∈ (𝐴 ∩ 𝐵)(𝐹‘𝑥) = 𝐶)

Distinct variable groups:   𝑥,𝐴   𝑥,𝐵   𝑥,𝐶

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

Proof of Theorem fvelimad

Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		fvelimad.c	. . . 4 ⊢ (𝜑 → 𝐶 ∈ (𝐹 “ 𝐵))
2		elimag 5470	. . . . 5 ⊢ (𝐶 ∈ (𝐹 “ 𝐵) → (𝐶 ∈ (𝐹 “ 𝐵) ↔ ∃𝑦 ∈ 𝐵 𝑦𝐹𝐶))
3	2	ibi 256	. . . 4 ⊢ (𝐶 ∈ (𝐹 “ 𝐵) → ∃𝑦 ∈ 𝐵 𝑦𝐹𝐶)
4	1, 3	syl 17	. . 3 ⊢ (𝜑 → ∃𝑦 ∈ 𝐵 𝑦𝐹𝐶)
5		nfv 1843	. . . 4 ⊢ Ⅎ𝑦𝜑
6		nfre1 3005	. . . 4 ⊢ Ⅎ𝑦∃𝑦 ∈ (𝐴 ∩ 𝐵)(𝐹‘𝑦) = 𝐶
7		vex 3203	. . . . . . . . . . 11 ⊢ 𝑦 ∈ V
8	7	a1i 11	. . . . . . . . . 10 ⊢ ((𝜑 ∧ 𝑦𝐹𝐶) → 𝑦 ∈ V)
9	1	adantr 481	. . . . . . . . . 10 ⊢ ((𝜑 ∧ 𝑦𝐹𝐶) → 𝐶 ∈ (𝐹 “ 𝐵))
10		simpr 477	. . . . . . . . . 10 ⊢ ((𝜑 ∧ 𝑦𝐹𝐶) → 𝑦𝐹𝐶)
11		breldmg 5330	. . . . . . . . . 10 ⊢ ((𝑦 ∈ V ∧ 𝐶 ∈ (𝐹 “ 𝐵) ∧ 𝑦𝐹𝐶) → 𝑦 ∈ dom 𝐹)
12	8, 9, 10, 11	syl3anc 1326	. . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑦𝐹𝐶) → 𝑦 ∈ dom 𝐹)
13		fvelimad.f	. . . . . . . . . . 11 ⊢ (𝜑 → 𝐹 Fn 𝐴)
14	13	fndmd 39441	. . . . . . . . . 10 ⊢ (𝜑 → dom 𝐹 = 𝐴)
15	14	adantr 481	. . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑦𝐹𝐶) → dom 𝐹 = 𝐴)
16	12, 15	eleqtrd 2703	. . . . . . . 8 ⊢ ((𝜑 ∧ 𝑦𝐹𝐶) → 𝑦 ∈ 𝐴)
17	16	3adant2 1080	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐵 ∧ 𝑦𝐹𝐶) → 𝑦 ∈ 𝐴)
18		simp2 1062	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐵 ∧ 𝑦𝐹𝐶) → 𝑦 ∈ 𝐵)
19	17, 18	elind 3798	. . . . . 6 ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐵 ∧ 𝑦𝐹𝐶) → 𝑦 ∈ (𝐴 ∩ 𝐵))
20		fnfun 5988	. . . . . . . . 9 ⊢ (𝐹 Fn 𝐴 → Fun 𝐹)
21	13, 20	syl 17	. . . . . . . 8 ⊢ (𝜑 → Fun 𝐹)
22	21	3ad2ant1 1082	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐵 ∧ 𝑦𝐹𝐶) → Fun 𝐹)
23		simp3 1063	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐵 ∧ 𝑦𝐹𝐶) → 𝑦𝐹𝐶)
24		funbrfv 6234	. . . . . . 7 ⊢ (Fun 𝐹 → (𝑦𝐹𝐶 → (𝐹‘𝑦) = 𝐶))
25	22, 23, 24	sylc 65	. . . . . 6 ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐵 ∧ 𝑦𝐹𝐶) → (𝐹‘𝑦) = 𝐶)
26		rspe 3003	. . . . . 6 ⊢ ((𝑦 ∈ (𝐴 ∩ 𝐵) ∧ (𝐹‘𝑦) = 𝐶) → ∃𝑦 ∈ (𝐴 ∩ 𝐵)(𝐹‘𝑦) = 𝐶)
27	19, 25, 26	syl2anc 693	. . . . 5 ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐵 ∧ 𝑦𝐹𝐶) → ∃𝑦 ∈ (𝐴 ∩ 𝐵)(𝐹‘𝑦) = 𝐶)
28	27	3exp 1264	. . . 4 ⊢ (𝜑 → (𝑦 ∈ 𝐵 → (𝑦𝐹𝐶 → ∃𝑦 ∈ (𝐴 ∩ 𝐵)(𝐹‘𝑦) = 𝐶)))
29	5, 6, 28	rexlimd 3026	. . 3 ⊢ (𝜑 → (∃𝑦 ∈ 𝐵 𝑦𝐹𝐶 → ∃𝑦 ∈ (𝐴 ∩ 𝐵)(𝐹‘𝑦) = 𝐶))
30	4, 29	mpd 15	. 2 ⊢ (𝜑 → ∃𝑦 ∈ (𝐴 ∩ 𝐵)(𝐹‘𝑦) = 𝐶)
31		nfv 1843	. . 3 ⊢ Ⅎ𝑦(𝐹‘𝑥) = 𝐶
32		fvelimad.x	. . . . 5 ⊢ Ⅎ𝑥𝐹
33		nfcv 2764	. . . . 5 ⊢ Ⅎ𝑥𝑦
34	32, 33	nffv 6198	. . . 4 ⊢ Ⅎ𝑥(𝐹‘𝑦)
35		nfcv 2764	. . . 4 ⊢ Ⅎ𝑥𝐶
36	34, 35	nfeq 2776	. . 3 ⊢ Ⅎ𝑥(𝐹‘𝑦) = 𝐶
37		fveq2 6191	. . . 4 ⊢ (𝑥 = 𝑦 → (𝐹‘𝑥) = (𝐹‘𝑦))
38	37	eqeq1d 2624	. . 3 ⊢ (𝑥 = 𝑦 → ((𝐹‘𝑥) = 𝐶 ↔ (𝐹‘𝑦) = 𝐶))
39	31, 36, 38	cbvrex 3168	. 2 ⊢ (∃𝑥 ∈ (𝐴 ∩ 𝐵)(𝐹‘𝑥) = 𝐶 ↔ ∃𝑦 ∈ (𝐴 ∩ 𝐵)(𝐹‘𝑦) = 𝐶)
40	30, 39	sylibr 224	1 ⊢ (𝜑 → ∃𝑥 ∈ (𝐴 ∩ 𝐵)(𝐹‘𝑥) = 𝐶)

Syntax hints:   → wi 4   ∧ wa 384   ∧ w3a 1037   = wceq 1483   ∈ wcel 1990  Ⅎwnfc 2751  ∃wrex 2913  Vcvv 3200   ∩ cin 3573   class class class wbr 4653  dom cdm 5114   “ cima 5117  Fun wfun 5882   Fn wfn 5883  ‘cfv 5888

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-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-sep 4781  ax-nul 4789  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-ral 2917  df-rex 2918  df-rab 2921  df-v 3202  df-sbc 3436  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-br 4654  df-opab 4713  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-fv 5896

This theorem is referenced by:  limsupmnflem  39952  liminfvalxr  40015