Theorem exbid 2224

Description: Formula-building rule for existential quantifier (deduction form). (Contributed by Mario Carneiro, 24-Sep-2016.)

Hypotheses

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

Assertion

Ref	Expression
exbid	⊢ (𝜑 → (∃𝑥𝜓 ↔ ∃𝑥𝜒))

Proof of Theorem exbid

Step	Hyp	Ref	Expression
1		albid.1	. . 3 ⊢ Ⅎ𝑥𝜑
2	1	nf5ri 2196	. 2 ⊢ (𝜑 → ∀𝑥𝜑)
3		albid.2	. 2 ⊢ (𝜑 → (𝜓 ↔ 𝜒))
4	2, 3	exbidh 1867	1 ⊢ (𝜑 → (∃𝑥𝜓 ↔ ∃𝑥𝜒))

Syntax hints:   → wi 4   ↔ wb 206  ∃wex 1779  Ⅎwnf 1783

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2008  ax-12 2178

This theorem depends on definitions:  df-bi 207  df-ex 1780  df-nf 1784

This theorem is referenced by:  nfbidf  2225  drex2  2440  rexbida  3247  rexeqfOLD  3328  opabbid  5167  zfrepclf  5241  dfid3  5529  oprabbid  7434  axrepndlem1  10521  axrepndlem2  10522  axrepnd  10523  axpowndlem2  10527  axpowndlem3  10528  axpowndlem4  10529  axregnd  10533  axinfndlem1  10534  axinfnd  10535  axacndlem4  10539  axacndlem5  10540  axacnd  10541  opabdm  32589  opabrn  32590  pm14.122b  44405  pm14.123b  44408  modelaxreplem3  44963