Theorem rexbid 3270

Description: Formula-building rule for restricted existential quantifier (deduction form). For a version based on fewer axioms see rexbidv 3177. (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 480	. 2 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (𝜓 ↔ 𝜒))
4	1, 3	rexbida 3268	1 ⊢ (𝜑 → (∃𝑥 ∈ 𝐴 𝜓 ↔ ∃𝑥 ∈ 𝐴 𝜒))

Syntax hints:   → wi 4   ↔ wb 205  Ⅎwnf 1784   ∈ wcel 2105  ∃wrex 3069

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1912  ax-6 1970  ax-7 2010  ax-12 2170

This theorem depends on definitions:  df-bi 206  df-an 396  df-ex 1781  df-nf 1785  df-rex 3070

This theorem is referenced by:  rexbidvALT  3271  rexeqbid  3352  scott0  9887  infcvgaux1i  15810  bnj1463  34530  fvineqsneq  36757  poimirlem25  36977  poimirlem26  36978  elrnmptf  44339  smfsupmpt  45990  smfinfmpt  45994