Theorem ralralimp 48484

Description: Selecting one of two alternatives within a restricted generalization if one of the alternatives is false. (Contributed by AV, 6-Sep-2018.) (Proof shortened by AV, 13-Oct-2018.)

Assertion

Ref	Expression
ralralimp	⊢ ((𝜑 ∧ 𝐴 ≠ ∅) → (∀𝑥 ∈ 𝐴 ((𝜑 → (𝜃 ∨ 𝜏)) ∧ ¬ 𝜃) → 𝜏))

Distinct variable groups:   𝑥,𝐴   𝜑,𝑥   𝜏,𝑥

Allowed substitution hint:   𝜃(𝑥)

Proof of Theorem ralralimp

Step	Hyp	Ref	Expression
1		ornld 1077	. . . 4 ⊢ (𝜑 → (((𝜑 → (𝜃 ∨ 𝜏)) ∧ ¬ 𝜃) → 𝜏))
2	1	adantr 486	. . 3 ⊢ ((𝜑 ∧ 𝐴 ≠ ∅) → (((𝜑 → (𝜃 ∨ 𝜏)) ∧ ¬ 𝜃) → 𝜏))
3	2	ralimdv 3176	. 2 ⊢ ((𝜑 ∧ 𝐴 ≠ ∅) → (∀𝑥 ∈ 𝐴 ((𝜑 → (𝜃 ∨ 𝜏)) ∧ ¬ 𝜃) → ∀𝑥 ∈ 𝐴 𝜏))
4		rspn0 4303	. . 3 ⊢ (𝐴 ≠ ∅ → (∀𝑥 ∈ 𝐴 𝜏 → 𝜏))
5	4	adantl 487	. 2 ⊢ ((𝜑 ∧ 𝐴 ≠ ∅) → (∀𝑥 ∈ 𝐴 𝜏 → 𝜏))
6	3, 5	syld 48	1 ⊢ ((𝜑 ∧ 𝐴 ≠ ∅) → (∀𝑥 ∈ 𝐴 ((𝜑 → (𝜃 ∨ 𝜏)) ∧ ¬ 𝜃) → 𝜏))

This proof depends on syntax axioms:  ¬ wn 3   → wi 4   ∧ wa 401   ∨ wo 861   ≠ wne 2955  ∀wral 3076  ∅c0 4277

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1827  ax-4 1841  ax-5 1942  ax-6 1999  ax-7 2040  ax-9 2154  ax-ext 2732

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-tru 1572  df-fal 1582  df-ex 1812  df-sb 2099  df-clab 2739  df-cleq 2752  df-ne 2956  df-ral 3077  df-dif 4046  df-nul 4278

This theorem is used by: (None)