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Mirrors > Home > MPE Home > Th. List > ralidmOLD | Structured version Visualization version GIF version |
Description: Obsolete version of ralidm 4442 as of 2-Sep-2024. (Contributed by NM, 28-Mar-1997.) (Proof modification is discouraged.) (New usage is discouraged.) |
Ref | Expression |
---|---|
ralidmOLD | ⊢ (∀𝑥 ∈ 𝐴 ∀𝑥 ∈ 𝐴 𝜑 ↔ ∀𝑥 ∈ 𝐴 𝜑) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | rzal 4439 | . . 3 ⊢ (𝐴 = ∅ → ∀𝑥 ∈ 𝐴 ∀𝑥 ∈ 𝐴 𝜑) | |
2 | rzal 4439 | . . 3 ⊢ (𝐴 = ∅ → ∀𝑥 ∈ 𝐴 𝜑) | |
3 | 1, 2 | 2thd 264 | . 2 ⊢ (𝐴 = ∅ → (∀𝑥 ∈ 𝐴 ∀𝑥 ∈ 𝐴 𝜑 ↔ ∀𝑥 ∈ 𝐴 𝜑)) |
4 | neq0 4279 | . . 3 ⊢ (¬ 𝐴 = ∅ ↔ ∃𝑥 𝑥 ∈ 𝐴) | |
5 | df-ral 3069 | . . . . 5 ⊢ (∀𝑥 ∈ 𝐴 ∀𝑥 ∈ 𝐴 𝜑 ↔ ∀𝑥(𝑥 ∈ 𝐴 → ∀𝑥 ∈ 𝐴 𝜑)) | |
6 | nfra1 3144 | . . . . . 6 ⊢ Ⅎ𝑥∀𝑥 ∈ 𝐴 𝜑 | |
7 | 6 | 19.23 2204 | . . . . 5 ⊢ (∀𝑥(𝑥 ∈ 𝐴 → ∀𝑥 ∈ 𝐴 𝜑) ↔ (∃𝑥 𝑥 ∈ 𝐴 → ∀𝑥 ∈ 𝐴 𝜑)) |
8 | 5, 7 | bitri 274 | . . . 4 ⊢ (∀𝑥 ∈ 𝐴 ∀𝑥 ∈ 𝐴 𝜑 ↔ (∃𝑥 𝑥 ∈ 𝐴 → ∀𝑥 ∈ 𝐴 𝜑)) |
9 | biimt 361 | . . . 4 ⊢ (∃𝑥 𝑥 ∈ 𝐴 → (∀𝑥 ∈ 𝐴 𝜑 ↔ (∃𝑥 𝑥 ∈ 𝐴 → ∀𝑥 ∈ 𝐴 𝜑))) | |
10 | 8, 9 | bitr4id 290 | . . 3 ⊢ (∃𝑥 𝑥 ∈ 𝐴 → (∀𝑥 ∈ 𝐴 ∀𝑥 ∈ 𝐴 𝜑 ↔ ∀𝑥 ∈ 𝐴 𝜑)) |
11 | 4, 10 | sylbi 216 | . 2 ⊢ (¬ 𝐴 = ∅ → (∀𝑥 ∈ 𝐴 ∀𝑥 ∈ 𝐴 𝜑 ↔ ∀𝑥 ∈ 𝐴 𝜑)) |
12 | 3, 11 | pm2.61i 182 | 1 ⊢ (∀𝑥 ∈ 𝐴 ∀𝑥 ∈ 𝐴 𝜑 ↔ ∀𝑥 ∈ 𝐴 𝜑) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ↔ wb 205 ∀wal 1537 = wceq 1539 ∃wex 1782 ∈ wcel 2106 ∀wral 3064 ∅c0 4256 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1798 ax-4 1812 ax-5 1913 ax-6 1971 ax-7 2011 ax-9 2116 ax-10 2137 ax-12 2171 ax-ext 2709 |
This theorem depends on definitions: df-bi 206 df-an 397 df-or 845 df-tru 1542 df-fal 1552 df-ex 1783 df-nf 1787 df-sb 2068 df-clab 2716 df-cleq 2730 df-ral 3069 df-dif 3890 df-nul 4257 |
This theorem is referenced by: (None) |
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