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| Mirrors > Home > MPE Home > Th. List > Mathboxes > ensucne0 | Structured version Visualization version GIF version | ||
| Description: A class equinumerous to a successor is never empty. (Contributed by RP, 11-Nov-2023.) (Proof shortened by SN, 16-Nov-2023.) |
| Ref | Expression |
|---|---|
| ensucne0 | ⊢ (𝐴 ≈ suc 𝐵 → 𝐴 ≠ ∅) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | nsuceq0 6420 | . . . 4 ⊢ suc 𝐵 ≠ ∅ | |
| 2 | en0r 8994 | . . . 4 ⊢ (∅ ≈ suc 𝐵 ↔ suc 𝐵 = ∅) | |
| 3 | 1, 2 | nemtbir 3022 | . . 3 ⊢ ¬ ∅ ≈ suc 𝐵 |
| 4 | breq1 5113 | . . 3 ⊢ (𝐴 = ∅ → (𝐴 ≈ suc 𝐵 ↔ ∅ ≈ suc 𝐵)) | |
| 5 | 3, 4 | mtbiri 327 | . 2 ⊢ (𝐴 = ∅ → ¬ 𝐴 ≈ suc 𝐵) |
| 6 | 5 | necon2ai 2955 | 1 ⊢ (𝐴 ≈ suc 𝐵 → 𝐴 ≠ ∅) |
| Colors of variables: wff setvar class |
| Syntax hints: → wi 4 = wceq 1540 ≠ wne 2926 ∅c0 4299 class class class wbr 5110 suc csuc 6337 ≈ cen 8918 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1795 ax-4 1809 ax-5 1910 ax-6 1967 ax-7 2008 ax-8 2111 ax-9 2119 ax-12 2178 ax-ext 2702 ax-sep 5254 ax-nul 5264 ax-pr 5390 |
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3an 1088 df-tru 1543 df-fal 1553 df-ex 1780 df-sb 2066 df-mo 2534 df-clab 2709 df-cleq 2722 df-clel 2804 df-ne 2927 df-ral 3046 df-rex 3055 df-rab 3409 df-v 3452 df-dif 3920 df-un 3922 df-ss 3934 df-nul 4300 df-if 4492 df-sn 4593 df-pr 4595 df-op 4599 df-br 5111 df-opab 5173 df-id 5536 df-xp 5647 df-rel 5648 df-cnv 5649 df-co 5650 df-dm 5651 df-rn 5652 df-suc 6341 df-fun 6516 df-fn 6517 df-f 6518 df-f1 6519 df-fo 6520 df-f1o 6521 df-en 8922 |
| This theorem is referenced by: (None) |
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