Theorem rsp3eq 38871

Description: From a restricted universal statement over 𝐴, specialize to an arbitrary element class, cf. rsp3 38870. (Contributed by Peter Mazsa, 9-Feb-2026.)

Hypotheses

Ref	Expression
rsp3.1	⊢ Ⅎ𝑥𝐴
rsp3.2	⊢ Ⅎ𝑦𝐴
rsp3.3	⊢ Ⅎ𝑦𝜑
rsp3.4	⊢ Ⅎ𝑥𝜓
rsp3.5	⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜓))

Assertion

Ref	Expression
rsp3eq	⊢ (∀𝑥 ∈ 𝐴 𝜑 → ((𝑦 = 𝐵 ∧ 𝐵 ∈ 𝐴) → 𝜓))

Distinct variable group:   𝑥,𝑦

Allowed substitution hints:   𝜑(𝑥,𝑦)   𝜓(𝑥,𝑦)   𝐴(𝑥,𝑦)   𝐵(𝑥,𝑦)

Proof of Theorem rsp3eq

Step	Hyp	Ref	Expression
1		eqeltr 38744	. 2 ⊢ ((𝑦 = 𝐵 ∧ 𝐵 ∈ 𝐴) → 𝑦 ∈ 𝐴)
2		rsp3.1	. . 3 ⊢ Ⅎ𝑥𝐴
3		rsp3.2	. . 3 ⊢ Ⅎ𝑦𝐴
4		rsp3.3	. . 3 ⊢ Ⅎ𝑦𝜑
5		rsp3.4	. . 3 ⊢ Ⅎ𝑥𝜓
6		rsp3.5	. . 3 ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜓))
7	2, 3, 4, 5, 6	rsp3 38870	. 2 ⊢ (∀𝑥 ∈ 𝐴 𝜑 → (𝑦 ∈ 𝐴 → 𝜓))
8	1, 7	syl5 34	1 ⊢ (∀𝑥 ∈ 𝐴 𝜑 → ((𝑦 = 𝐵 ∧ 𝐵 ∈ 𝐴) → 𝜓))

Syntax hints:   → wi 4   ↔ wb 208   ∧ wa 399   = wceq 1562  Ⅎwnf 1805   ∈ wcel 2144  Ⅎwnfc 2911  ∀wral 3078

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1817  ax-4 1831  ax-5 1932  ax-6 1989  ax-7 2030  ax-8 2146  ax-9 2154  ax-11 2193  ax-12 2214  ax-ext 2736

This theorem depends on definitions:  df-bi 209  df-an 400  df-ex 1802  df-nf 1806  df-cleq 2756  df-clel 2839  df-nfc 2913  df-ral 3079

This theorem is referenced by: (None)