Theorem 19.45v 1989

Description: Version of 19.45 2223 with a disjoint variable condition, requiring fewer axioms. (Contributed by NM, 12-Mar-1993.)

Assertion

Ref	Expression
19.45v	⊢ (∃𝑥(𝜑 ∨ 𝜓) ↔ (𝜑 ∨ ∃𝑥𝜓))

Distinct variable group:   𝜑,𝑥

Allowed substitution hint:   𝜓(𝑥)

Proof of Theorem 19.45v

Step	Hyp	Ref	Expression
1		19.43 1877	. 2 ⊢ (∃𝑥(𝜑 ∨ 𝜓) ↔ (∃𝑥𝜑 ∨ ∃𝑥𝜓))
2		19.9v 1979	. . 3 ⊢ (∃𝑥𝜑 ↔ 𝜑)
3	2	orbi1i 910	. 2 ⊢ ((∃𝑥𝜑 ∨ ∃𝑥𝜓) ↔ (𝜑 ∨ ∃𝑥𝜓))
4	1, 3	bitri 275	1 ⊢ (∃𝑥(𝜑 ∨ 𝜓) ↔ (𝜑 ∨ ∃𝑥𝜓))

Syntax hints:   ↔ wb 205   ∨ wo 844  ∃wex 1773

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

This theorem depends on definitions:  df-bi 206  df-or 845  df-ex 1774

This theorem is referenced by:  satfvsucsuc  34874  mosssn2  47749