Theorem rexbid 3261

Description: Formula-building rule for restricted existential quantifier (deduction form). For a version based on fewer axioms see rexbidv 3168. (Contributed by NM, 27-Jun-1998.)

Hypotheses

Ref	Expression
rexbid.1	⊢ Ⅎ𝑥𝜑
rexbid.2	⊢ (𝜑 → (𝜓 ↔ 𝜒))

Assertion

Ref	Expression
rexbid	⊢ (𝜑 → (∃𝑥 ∈ 𝐴 𝜓 ↔ ∃𝑥 ∈ 𝐴 𝜒))

Proof of Theorem rexbid

Step	Hyp	Ref	Expression
1		rexbid.1	. 2 ⊢ Ⅎ𝑥𝜑
2		rexbid.2	. . 3 ⊢ (𝜑 → (𝜓 ↔ 𝜒))
3	2	adantr 479	. 2 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (𝜓 ↔ 𝜒))
4	1, 3	rexbida 3259	1 ⊢ (𝜑 → (∃𝑥 ∈ 𝐴 𝜓 ↔ ∃𝑥 ∈ 𝐴 𝜒))

Syntax hints:   → wi 4   ↔ wb 205  Ⅎwnf 1777   ∈ wcel 2098  ∃wrex 3059

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1789  ax-4 1803  ax-5 1905  ax-6 1963  ax-7 2003  ax-12 2166

This theorem depends on definitions:  df-bi 206  df-an 395  df-ex 1774  df-nf 1778  df-rex 3060

This theorem is referenced by:  rexbidvALT  3262  rexeqbid  3340  scott0  9925  infcvgaux1i  15856  bnj1463  34856  fvineqsneq  37067  poimirlem25  37294  poimirlem26  37295  elrnmptf  44725  smfsupmpt  46373  smfinfmpt  46377