Mathbox for Wolf Lammen |
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Mirrors > Home > MPE Home > Th. List > Mathboxes > wl-mo2t | Structured version Visualization version GIF version |
Description: Closed form of mo2 2479. (Contributed by Wolf Lammen, 18-Aug-2019.) |
Ref | Expression |
---|---|
wl-mo2t | ⊢ (∀𝑥Ⅎ𝑦𝜑 → (∃*𝑥𝜑 ↔ ∃𝑦∀𝑥(𝜑 → 𝑥 = 𝑦))) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | mo2v 2477 | . 2 ⊢ (∃*𝑥𝜑 ↔ ∃𝑢∀𝑥(𝜑 → 𝑥 = 𝑢)) | |
2 | nfnf1 2031 | . . . 4 ⊢ Ⅎ𝑦Ⅎ𝑦𝜑 | |
3 | 2 | nfal 2153 | . . 3 ⊢ Ⅎ𝑦∀𝑥Ⅎ𝑦𝜑 |
4 | nfa1 2028 | . . . 4 ⊢ Ⅎ𝑥∀𝑥Ⅎ𝑦𝜑 | |
5 | sp 2053 | . . . . 5 ⊢ (∀𝑥Ⅎ𝑦𝜑 → Ⅎ𝑦𝜑) | |
6 | nfvd 1844 | . . . . 5 ⊢ (∀𝑥Ⅎ𝑦𝜑 → Ⅎ𝑦 𝑥 = 𝑢) | |
7 | 5, 6 | nfimd 1823 | . . . 4 ⊢ (∀𝑥Ⅎ𝑦𝜑 → Ⅎ𝑦(𝜑 → 𝑥 = 𝑢)) |
8 | 4, 7 | nfald 2165 | . . 3 ⊢ (∀𝑥Ⅎ𝑦𝜑 → Ⅎ𝑦∀𝑥(𝜑 → 𝑥 = 𝑢)) |
9 | equequ2 1953 | . . . . . 6 ⊢ (𝑢 = 𝑦 → (𝑥 = 𝑢 ↔ 𝑥 = 𝑦)) | |
10 | 9 | imbi2d 330 | . . . . 5 ⊢ (𝑢 = 𝑦 → ((𝜑 → 𝑥 = 𝑢) ↔ (𝜑 → 𝑥 = 𝑦))) |
11 | 10 | albidv 1849 | . . . 4 ⊢ (𝑢 = 𝑦 → (∀𝑥(𝜑 → 𝑥 = 𝑢) ↔ ∀𝑥(𝜑 → 𝑥 = 𝑦))) |
12 | 11 | a1i 11 | . . 3 ⊢ (∀𝑥Ⅎ𝑦𝜑 → (𝑢 = 𝑦 → (∀𝑥(𝜑 → 𝑥 = 𝑢) ↔ ∀𝑥(𝜑 → 𝑥 = 𝑦)))) |
13 | 3, 8, 12 | cbvexd 2278 | . 2 ⊢ (∀𝑥Ⅎ𝑦𝜑 → (∃𝑢∀𝑥(𝜑 → 𝑥 = 𝑢) ↔ ∃𝑦∀𝑥(𝜑 → 𝑥 = 𝑦))) |
14 | 1, 13 | syl5bb 272 | 1 ⊢ (∀𝑥Ⅎ𝑦𝜑 → (∃*𝑥𝜑 ↔ ∃𝑦∀𝑥(𝜑 → 𝑥 = 𝑦))) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 196 ∀wal 1481 ∃wex 1704 Ⅎwnf 1708 ∃*wmo 2471 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1722 ax-4 1737 ax-5 1839 ax-6 1888 ax-7 1935 ax-10 2019 ax-11 2034 ax-12 2047 ax-13 2246 |
This theorem depends on definitions: df-bi 197 df-or 385 df-an 386 df-ex 1705 df-nf 1710 df-eu 2474 df-mo 2475 |
This theorem is referenced by: wl-mo3t 33358 |
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