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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 6447 | . . . 4 ⊢ suc 𝐵 ≠ ∅ | |
2 | en0r 9015 | . . . 4 ⊢ (∅ ≈ suc 𝐵 ↔ suc 𝐵 = ∅) | |
3 | 1, 2 | nemtbir 3038 | . . 3 ⊢ ¬ ∅ ≈ suc 𝐵 |
4 | breq1 5151 | . . 3 ⊢ (𝐴 = ∅ → (𝐴 ≈ suc 𝐵 ↔ ∅ ≈ suc 𝐵)) | |
5 | 3, 4 | mtbiri 326 | . 2 ⊢ (𝐴 = ∅ → ¬ 𝐴 ≈ suc 𝐵) |
6 | 5 | necon2ai 2970 | 1 ⊢ (𝐴 ≈ suc 𝐵 → 𝐴 ≠ ∅) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 = wceq 1541 ≠ wne 2940 ∅c0 4322 class class class wbr 5148 suc csuc 6366 ≈ cen 8935 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1797 ax-4 1811 ax-5 1913 ax-6 1971 ax-7 2011 ax-8 2108 ax-9 2116 ax-12 2171 ax-ext 2703 ax-sep 5299 ax-nul 5306 ax-pr 5427 |
This theorem depends on definitions: df-bi 206 df-an 397 df-or 846 df-3an 1089 df-tru 1544 df-fal 1554 df-ex 1782 df-sb 2068 df-mo 2534 df-clab 2710 df-cleq 2724 df-clel 2810 df-ne 2941 df-ral 3062 df-rex 3071 df-rab 3433 df-v 3476 df-dif 3951 df-un 3953 df-in 3955 df-ss 3965 df-nul 4323 df-if 4529 df-sn 4629 df-pr 4631 df-op 4635 df-br 5149 df-opab 5211 df-id 5574 df-xp 5682 df-rel 5683 df-cnv 5684 df-co 5685 df-dm 5686 df-rn 5687 df-suc 6370 df-fun 6545 df-fn 6546 df-f 6547 df-f1 6548 df-fo 6549 df-f1o 6550 df-en 8939 |
This theorem is referenced by: (None) |
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