Theorem r19.41 3309

Description: Restricted quantifier version of 19.41 2202. See r19.41v 3308 for a version with a disjoint variable condition, requiring fewer axioms. (Contributed by NM, 1-Nov-2010.)

Hypothesis

Ref	Expression
r19.41.1	⊢ Ⅎ𝑥𝜓

Assertion

Ref	Expression
r19.41	⊢ (∃𝑥 ∈ 𝐴 (𝜑 ∧ 𝜓) ↔ (∃𝑥 ∈ 𝐴 𝜑 ∧ 𝜓))

Proof of Theorem r19.41

Step	Hyp	Ref	Expression
1		anass 469	. . . 4 ⊢ (((𝑥 ∈ 𝐴 ∧ 𝜑) ∧ 𝜓) ↔ (𝑥 ∈ 𝐴 ∧ (𝜑 ∧ 𝜓)))
2	1	exbii 1829	. . 3 ⊢ (∃𝑥((𝑥 ∈ 𝐴 ∧ 𝜑) ∧ 𝜓) ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ (𝜑 ∧ 𝜓)))
3		r19.41.1	. . . 4 ⊢ Ⅎ𝑥𝜓
4	3	19.41 2202	. . 3 ⊢ (∃𝑥((𝑥 ∈ 𝐴 ∧ 𝜑) ∧ 𝜓) ↔ (∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑) ∧ 𝜓))
5	2, 4	bitr3i 278	. 2 ⊢ (∃𝑥(𝑥 ∈ 𝐴 ∧ (𝜑 ∧ 𝜓)) ↔ (∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑) ∧ 𝜓))
6		df-rex 3111	. 2 ⊢ (∃𝑥 ∈ 𝐴 (𝜑 ∧ 𝜓) ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ (𝜑 ∧ 𝜓)))
7		df-rex 3111	. . 3 ⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑))
8	7	anbi1i 623	. 2 ⊢ ((∃𝑥 ∈ 𝐴 𝜑 ∧ 𝜓) ↔ (∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑) ∧ 𝜓))
9	5, 6, 8	3bitr4i 304	1 ⊢ (∃𝑥 ∈ 𝐴 (𝜑 ∧ 𝜓) ↔ (∃𝑥 ∈ 𝐴 𝜑 ∧ 𝜓))

Syntax hints:   ↔ wb 207   ∧ wa 396  ∃wex 1761  Ⅎwnf 1765   ∈ wcel 2081  ∃wrex 3106

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1777  ax-4 1791  ax-5 1888  ax-6 1947  ax-7 1992  ax-12 2141

This theorem depends on definitions:  df-bi 208  df-an 397  df-ex 1762  df-nf 1766  df-rex 3111

This theorem is referenced by:  reuxfrdf  29952  iunin1f  30004  2reu8i  42854