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| Mirrors > Home > ILE Home > Th. List > Mathboxes > nfalseu | GIF version | ||
| Description: Bound-variable hypothesis builder for "all some one". This is the "all some one" counterpart of nfals 17118. Unlike the set.mm version of this theorem, no disjoint variable condition is needed, because nfeu 2105 here does not require one. (Contributed by David A. Wheeler, 22-Jul-2026.) |
| Ref | Expression |
|---|---|
| nfalseu.1 | ⊢ Ⅎ𝑥𝜑 |
| nfalseu.2 | ⊢ Ⅎ𝑥𝜓 |
| Ref | Expression |
|---|---|
| nfalseu | ⊢ Ⅎ𝑥∀∃!𝑦(𝜑 → 𝜓) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-alseu 17136 | . 2 ⊢ (∀∃!𝑦(𝜑 → 𝜓) ↔ (∀𝑦(𝜑 → 𝜓) ∧ ∃!𝑦𝜑)) | |
| 2 | nfalseu.1 | . . . . 5 ⊢ Ⅎ𝑥𝜑 | |
| 3 | nfalseu.2 | . . . . 5 ⊢ Ⅎ𝑥𝜓 | |
| 4 | 2, 3 | nfim 1625 | . . . 4 ⊢ Ⅎ𝑥(𝜑 → 𝜓) |
| 5 | 4 | nfal 1629 | . . 3 ⊢ Ⅎ𝑥∀𝑦(𝜑 → 𝜓) |
| 6 | 2 | nfeu 2105 | . . 3 ⊢ Ⅎ𝑥∃!𝑦𝜑 |
| 7 | 5, 6 | nfan 1618 | . 2 ⊢ Ⅎ𝑥(∀𝑦(𝜑 → 𝜓) ∧ ∃!𝑦𝜑) |
| 8 | 1, 7 | nfxfr 1527 | 1 ⊢ Ⅎ𝑥∀∃!𝑦(𝜑 → 𝜓) |
| Colors of variables: wff set class |
| Syntax hints: → wi 4 ∧ wa 104 ∀wal 1400 Ⅎwnf 1513 ∃!weu 2086 ∀∃!walseu 17134 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-io 721 ax-5 1500 ax-7 1501 ax-gen 1502 ax-ie1 1546 ax-ie2 1547 ax-8 1557 ax-10 1558 ax-11 1559 ax-i12 1560 ax-bndl 1562 ax-4 1563 ax-17 1579 ax-i9 1583 ax-ial 1587 ax-i5r 1588 |
| This theorem depends on definitions: df-bi 117 df-tru 1405 df-nf 1514 df-sb 1816 df-eu 2089 df-alseu 17136 |
| This theorem is referenced by: (None) |
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