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| Mirrors > Home > MPE Home > Th. List > Mathboxes > iotan0aiotaex | Structured version Visualization version GIF version | ||
| Description: If the iota over a wff 𝜑 is not empty, the alternate iota over 𝜑 is a set. (Contributed by AV, 25-Aug-2022.) |
| Ref | Expression |
|---|---|
| iotan0aiotaex | ⊢ ((℩𝑥𝜑) ≠ ∅ → (℩'𝑥𝜑) ∈ V) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | iotanul 6461 | . . 3 ⊢ (¬ ∃!𝑥𝜑 → (℩𝑥𝜑) = ∅) | |
| 2 | 1 | necon1ai 2955 | . 2 ⊢ ((℩𝑥𝜑) ≠ ∅ → ∃!𝑥𝜑) |
| 3 | aiotaexb 47128 | . 2 ⊢ (∃!𝑥𝜑 ↔ (℩'𝑥𝜑) ∈ V) | |
| 4 | 2, 3 | sylib 218 | 1 ⊢ ((℩𝑥𝜑) ≠ ∅ → (℩'𝑥𝜑) ∈ V) |
| Colors of variables: wff setvar class |
| Syntax hints: → wi 4 ∈ wcel 2111 ∃!weu 2563 ≠ wne 2928 Vcvv 3436 ∅c0 4280 ℩cio 6435 ℩'caiota 47122 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1796 ax-4 1810 ax-5 1911 ax-6 1968 ax-7 2009 ax-8 2113 ax-9 2121 ax-10 2144 ax-11 2160 ax-12 2180 ax-ext 2703 ax-sep 5232 |
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3an 1088 df-tru 1544 df-fal 1554 df-ex 1781 df-nf 1785 df-sb 2068 df-mo 2535 df-eu 2564 df-clab 2710 df-cleq 2723 df-clel 2806 df-ne 2929 df-ral 3048 df-rex 3057 df-rab 3396 df-v 3438 df-dif 3900 df-in 3904 df-ss 3914 df-nul 4281 df-sn 4574 df-uni 4857 df-int 4896 df-iota 6437 df-aiota 47124 |
| This theorem is referenced by: (None) |
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