Theorem opnneilv 49342

Description: The converse of opnneir 49340 with different dummy variables. Note that the second hypothesis could be generalized by adding 𝑦 ∈ 𝐽 to the antecedent. See the proof for details. Although 𝐽 ∈ Top might be redundant here (see neircl 49338), it is listed for explicitness. (Contributed by Zhi Wang, 31-Aug-2024.)

Hypotheses

Ref	Expression
opnneir.1	⊢ (𝜑 → 𝐽 ∈ Top)
opnneilv.2	⊢ ((𝜑 ∧ 𝑦 ⊆ 𝑥) → (𝜓 → 𝜒))

Assertion

Ref	Expression
opnneilv	⊢ (𝜑 → (∃𝑥 ∈ ((nei‘𝐽)‘𝑆)𝜓 → ∃𝑦 ∈ 𝐽 (𝑆 ⊆ 𝑦 ∧ 𝜒)))

Distinct variable groups:   𝑥,𝐽,𝑦   𝑥,𝑆,𝑦   𝜒,𝑥   𝜑,𝑥,𝑦   𝜓,𝑦

Allowed substitution hints:   𝜓(𝑥)   𝜒(𝑦)

Proof of Theorem opnneilv

Step	Hyp	Ref	Expression
1		df-rex 3063	. 2 ⊢ (∃𝑥 ∈ ((nei‘𝐽)‘𝑆)𝜓 ↔ ∃𝑥(𝑥 ∈ ((nei‘𝐽)‘𝑆) ∧ 𝜓))
2		opnneir.1	. . . . . . 7 ⊢ (𝜑 → 𝐽 ∈ Top)
3		neii2 23051	. . . . . . 7 ⊢ ((𝐽 ∈ Top ∧ 𝑥 ∈ ((nei‘𝐽)‘𝑆)) → ∃𝑦 ∈ 𝐽 (𝑆 ⊆ 𝑦 ∧ 𝑦 ⊆ 𝑥))
4	2, 3	sylan 581	. . . . . 6 ⊢ ((𝜑 ∧ 𝑥 ∈ ((nei‘𝐽)‘𝑆)) → ∃𝑦 ∈ 𝐽 (𝑆 ⊆ 𝑦 ∧ 𝑦 ⊆ 𝑥))
5	4	r19.41dv 49235	. . . . 5 ⊢ (((𝜑 ∧ 𝑥 ∈ ((nei‘𝐽)‘𝑆)) ∧ 𝜓) → ∃𝑦 ∈ 𝐽 ((𝑆 ⊆ 𝑦 ∧ 𝑦 ⊆ 𝑥) ∧ 𝜓))
6	5	expl 457	. . . 4 ⊢ (𝜑 → ((𝑥 ∈ ((nei‘𝐽)‘𝑆) ∧ 𝜓) → ∃𝑦 ∈ 𝐽 ((𝑆 ⊆ 𝑦 ∧ 𝑦 ⊆ 𝑥) ∧ 𝜓)))
7		anass 468	. . . . . 6 ⊢ (((𝑆 ⊆ 𝑦 ∧ 𝑦 ⊆ 𝑥) ∧ 𝜓) ↔ (𝑆 ⊆ 𝑦 ∧ (𝑦 ⊆ 𝑥 ∧ 𝜓)))
8		opnneilv.2	. . . . . . . 8 ⊢ ((𝜑 ∧ 𝑦 ⊆ 𝑥) → (𝜓 → 𝜒))
9	8	expimpd 453	. . . . . . 7 ⊢ (𝜑 → ((𝑦 ⊆ 𝑥 ∧ 𝜓) → 𝜒))
10	9	anim2d 613	. . . . . 6 ⊢ (𝜑 → ((𝑆 ⊆ 𝑦 ∧ (𝑦 ⊆ 𝑥 ∧ 𝜓)) → (𝑆 ⊆ 𝑦 ∧ 𝜒)))
11	7, 10	biimtrid 242	. . . . 5 ⊢ (𝜑 → (((𝑆 ⊆ 𝑦 ∧ 𝑦 ⊆ 𝑥) ∧ 𝜓) → (𝑆 ⊆ 𝑦 ∧ 𝜒)))
12	11	reximdv 3153	. . . 4 ⊢ (𝜑 → (∃𝑦 ∈ 𝐽 ((𝑆 ⊆ 𝑦 ∧ 𝑦 ⊆ 𝑥) ∧ 𝜓) → ∃𝑦 ∈ 𝐽 (𝑆 ⊆ 𝑦 ∧ 𝜒)))
13	6, 12	syld 47	. . 3 ⊢ (𝜑 → ((𝑥 ∈ ((nei‘𝐽)‘𝑆) ∧ 𝜓) → ∃𝑦 ∈ 𝐽 (𝑆 ⊆ 𝑦 ∧ 𝜒)))
14	13	exlimdv 1935	. 2 ⊢ (𝜑 → (∃𝑥(𝑥 ∈ ((nei‘𝐽)‘𝑆) ∧ 𝜓) → ∃𝑦 ∈ 𝐽 (𝑆 ⊆ 𝑦 ∧ 𝜒)))
15	1, 14	biimtrid 242	1 ⊢ (𝜑 → (∃𝑥 ∈ ((nei‘𝐽)‘𝑆)𝜓 → ∃𝑦 ∈ 𝐽 (𝑆 ⊆ 𝑦 ∧ 𝜒)))

Syntax hints:   → wi 4   ∧ wa 395  ∃wex 1781   ∈ wcel 2114  ∃wrex 3062   ⊆ wss 3890  ‘cfv 6490  Topctop 22836  neicnei 23040

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1912  ax-6 1969  ax-7 2010  ax-8 2116  ax-9 2124  ax-10 2147  ax-11 2163  ax-12 2185  ax-ext 2709  ax-rep 5212  ax-sep 5231  ax-nul 5241  ax-pow 5300  ax-pr 5368

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 849  df-3an 1089  df-tru 1545  df-fal 1555  df-ex 1782  df-nf 1786  df-sb 2069  df-mo 2540  df-eu 2570  df-clab 2716  df-cleq 2729  df-clel 2812  df-nfc 2886  df-ne 2934  df-ral 3053  df-rex 3063  df-reu 3344  df-rab 3391  df-v 3432  df-sbc 3730  df-csb 3839  df-dif 3893  df-un 3895  df-in 3897  df-ss 3907  df-nul 4275  df-if 4468  df-pw 4544  df-sn 4569  df-pr 4571  df-op 4575  df-uni 4852  df-iun 4936  df-br 5087  df-opab 5149  df-mpt 5168  df-id 5517  df-xp 5628  df-rel 5629  df-cnv 5630  df-co 5631  df-dm 5632  df-rn 5633  df-res 5634  df-ima 5635  df-iota 6446  df-fun 6492  df-fn 6493  df-f 6494  df-f1 6495  df-fo 6496  df-f1o 6497  df-fv 6498  df-top 22837  df-nei 23041

This theorem is referenced by:  opnneil  49343