Theorem r19.30OLD 3339

Description: Obsolete version of r19.30 3338 as of 18-Jun-2023. (Contributed by Scott Fenton, 25-Feb-2011.) (Proof modification is discouraged.) (New usage is discouraged.)

Assertion

Ref	Expression
r19.30OLD	⊢ (∀𝑥 ∈ 𝐴 (𝜑 ∨ 𝜓) → (∀𝑥 ∈ 𝐴 𝜑 ∨ ∃𝑥 ∈ 𝐴 𝜓))

Proof of Theorem r19.30OLD

Step	Hyp	Ref	Expression
1		ralim 3162	. 2 ⊢ (∀𝑥 ∈ 𝐴 (¬ 𝜓 → 𝜑) → (∀𝑥 ∈ 𝐴 ¬ 𝜓 → ∀𝑥 ∈ 𝐴 𝜑))
2		orcom 866	. . . 4 ⊢ ((𝜑 ∨ 𝜓) ↔ (𝜓 ∨ 𝜑))
3		df-or 844	. . . 4 ⊢ ((𝜓 ∨ 𝜑) ↔ (¬ 𝜓 → 𝜑))
4	2, 3	bitri 277	. . 3 ⊢ ((𝜑 ∨ 𝜓) ↔ (¬ 𝜓 → 𝜑))
5	4	ralbii 3165	. 2 ⊢ (∀𝑥 ∈ 𝐴 (𝜑 ∨ 𝜓) ↔ ∀𝑥 ∈ 𝐴 (¬ 𝜓 → 𝜑))
6		orcom 866	. . 3 ⊢ ((∀𝑥 ∈ 𝐴 𝜑 ∨ ¬ ∀𝑥 ∈ 𝐴 ¬ 𝜓) ↔ (¬ ∀𝑥 ∈ 𝐴 ¬ 𝜓 ∨ ∀𝑥 ∈ 𝐴 𝜑))
7		dfrex2 3239	. . . 4 ⊢ (∃𝑥 ∈ 𝐴 𝜓 ↔ ¬ ∀𝑥 ∈ 𝐴 ¬ 𝜓)
8	7	orbi2i 909	. . 3 ⊢ ((∀𝑥 ∈ 𝐴 𝜑 ∨ ∃𝑥 ∈ 𝐴 𝜓) ↔ (∀𝑥 ∈ 𝐴 𝜑 ∨ ¬ ∀𝑥 ∈ 𝐴 ¬ 𝜓))
9		imor 849	. . 3 ⊢ ((∀𝑥 ∈ 𝐴 ¬ 𝜓 → ∀𝑥 ∈ 𝐴 𝜑) ↔ (¬ ∀𝑥 ∈ 𝐴 ¬ 𝜓 ∨ ∀𝑥 ∈ 𝐴 𝜑))
10	6, 8, 9	3bitr4i 305	. 2 ⊢ ((∀𝑥 ∈ 𝐴 𝜑 ∨ ∃𝑥 ∈ 𝐴 𝜓) ↔ (∀𝑥 ∈ 𝐴 ¬ 𝜓 → ∀𝑥 ∈ 𝐴 𝜑))
11	1, 5, 10	3imtr4i 294	1 ⊢ (∀𝑥 ∈ 𝐴 (𝜑 ∨ 𝜓) → (∀𝑥 ∈ 𝐴 𝜑 ∨ ∃𝑥 ∈ 𝐴 𝜓))

Syntax hints:  ¬ wn 3   → wi 4   ∨ wo 843  ∀wral 3138  ∃wrex 3139

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

This theorem depends on definitions:  df-bi 209  df-an 399  df-or 844  df-ex 1781  df-ral 3143  df-rex 3144

This theorem is referenced by: (None)