Theorem rspceb2dv 3581

Description: Restricted existential specialization, using implicit substitution in both directions. (Contributed by Zhi Wang, 28-Sep-2024.)

Hypotheses

Ref	Expression
rspceb2dv.1	⊢ ((𝜑 ∧ 𝑥 ∈ 𝐵) → (𝜓 → 𝜒))
rspceb2dv.2	⊢ ((𝜑 ∧ 𝜒) → 𝐴 ∈ 𝐵)
rspceb2dv.3	⊢ ((𝜑 ∧ 𝜒) → 𝜃)
rspceb2dv.4	⊢ (𝑥 = 𝐴 → (𝜓 ↔ 𝜃))

Assertion

Ref	Expression
rspceb2dv	⊢ (𝜑 → (∃𝑥 ∈ 𝐵 𝜓 ↔ 𝜒))

Distinct variable groups:   𝑥,𝐴   𝑥,𝐵   𝜒,𝑥   𝜑,𝑥   𝜃,𝑥

Allowed substitution hint:   𝜓(𝑥)

Proof of Theorem rspceb2dv

Step	Hyp	Ref	Expression
1		rspceb2dv.1	. . 3 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐵) → (𝜓 → 𝜒))
2	1	rexlimdva 3164	. 2 ⊢ (𝜑 → (∃𝑥 ∈ 𝐵 𝜓 → 𝜒))
3		rspceb2dv.4	. . . 4 ⊢ (𝑥 = 𝐴 → (𝜓 ↔ 𝜃))
4		rspceb2dv.2	. . . 4 ⊢ ((𝜑 ∧ 𝜒) → 𝐴 ∈ 𝐵)
5		rspceb2dv.3	. . . 4 ⊢ ((𝜑 ∧ 𝜒) → 𝜃)
6	3, 4, 5	rspcedvdw 3580	. . 3 ⊢ ((𝜑 ∧ 𝜒) → ∃𝑥 ∈ 𝐵 𝜓)
7	6	ex 418	. 2 ⊢ (𝜑 → (𝜒 → ∃𝑥 ∈ 𝐵 𝜓))
8	2, 7	impbid 215	1 ⊢ (𝜑 → (∃𝑥 ∈ 𝐵 𝜓 ↔ 𝜒))

This proof depends on syntax axioms:   → wi 4   ↔ wb 209   ∧ wa 401   = wceq 1570   ∈ wcel 2145  ∃wrex 3087

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-ext 2733

This proof depends on definitions:  df-bi 210  df-an 402  df-tru 1573  df-ex 1813  df-sb 2100  df-clab 2740  df-cleq 2753  df-clel 2836  df-ral 3078  df-rex 3088

This theorem is used by:  negfi  12266  psdmul  22487  uspgrlimlem1  49085  ipolubdm  50094  ipoglbdm  50097