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Mirrors > Home > ILE Home > Th. List > eupickbi | GIF version |
Description: Theorem *14.26 in [WhiteheadRussell] p. 192. (Contributed by Andrew Salmon, 11-Jul-2011.) |
Ref | Expression |
---|---|
eupickbi | ⊢ (∃!𝑥𝜑 → (∃𝑥(𝜑 ∧ 𝜓) ↔ ∀𝑥(𝜑 → 𝜓))) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eupicka 2080 | . . 3 ⊢ ((∃!𝑥𝜑 ∧ ∃𝑥(𝜑 ∧ 𝜓)) → ∀𝑥(𝜑 → 𝜓)) | |
2 | 1 | ex 114 | . 2 ⊢ (∃!𝑥𝜑 → (∃𝑥(𝜑 ∧ 𝜓) → ∀𝑥(𝜑 → 𝜓))) |
3 | hba1 1521 | . . . . 5 ⊢ (∀𝑥(𝜑 → 𝜓) → ∀𝑥∀𝑥(𝜑 → 𝜓)) | |
4 | ancl 316 | . . . . . . 7 ⊢ ((𝜑 → 𝜓) → (𝜑 → (𝜑 ∧ 𝜓))) | |
5 | simpl 108 | . . . . . . 7 ⊢ ((𝜑 ∧ 𝜓) → 𝜑) | |
6 | 4, 5 | impbid1 141 | . . . . . 6 ⊢ ((𝜑 → 𝜓) → (𝜑 ↔ (𝜑 ∧ 𝜓))) |
7 | 6 | sps 1518 | . . . . 5 ⊢ (∀𝑥(𝜑 → 𝜓) → (𝜑 ↔ (𝜑 ∧ 𝜓))) |
8 | 3, 7 | eubidh 2006 | . . . 4 ⊢ (∀𝑥(𝜑 → 𝜓) → (∃!𝑥𝜑 ↔ ∃!𝑥(𝜑 ∧ 𝜓))) |
9 | euex 2030 | . . . 4 ⊢ (∃!𝑥(𝜑 ∧ 𝜓) → ∃𝑥(𝜑 ∧ 𝜓)) | |
10 | 8, 9 | syl6bi 162 | . . 3 ⊢ (∀𝑥(𝜑 → 𝜓) → (∃!𝑥𝜑 → ∃𝑥(𝜑 ∧ 𝜓))) |
11 | 10 | com12 30 | . 2 ⊢ (∃!𝑥𝜑 → (∀𝑥(𝜑 → 𝜓) → ∃𝑥(𝜑 ∧ 𝜓))) |
12 | 2, 11 | impbid 128 | 1 ⊢ (∃!𝑥𝜑 → (∃𝑥(𝜑 ∧ 𝜓) ↔ ∀𝑥(𝜑 → 𝜓))) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 103 ↔ wb 104 ∀wal 1330 ∃wex 1469 ∃!weu 2000 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-io 699 ax-5 1424 ax-7 1425 ax-gen 1426 ax-ie1 1470 ax-ie2 1471 ax-8 1483 ax-10 1484 ax-11 1485 ax-i12 1486 ax-bndl 1487 ax-4 1488 ax-17 1507 ax-i9 1511 ax-ial 1515 ax-i5r 1516 |
This theorem depends on definitions: df-bi 116 df-nf 1438 df-sb 1737 df-eu 2003 df-mo 2004 |
This theorem is referenced by: (None) |
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