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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 6431 | . . . 4 ⊢ suc 𝐵 ≠ ∅ | |
| 2 | en0r 9001 | . . . 4 ⊢ (∅ ≈ suc 𝐵 ↔ suc 𝐵 = ∅) | |
| 3 | 1, 2 | nemtbir 3053 | . . 3 ⊢ ¬ ∅ ≈ suc 𝐵 |
| 4 | breq1 5103 | . . 3 ⊢ (𝐴 = ∅ → (𝐴 ≈ suc 𝐵 ↔ ∅ ≈ suc 𝐵)) | |
| 5 | 3, 4 | mtbiri 329 | . 2 ⊢ (𝐴 = ∅ → ¬ 𝐴 ≈ suc 𝐵) |
| 6 | 5 | necon2ai 2986 | 1 ⊢ (𝐴 ≈ suc 𝐵 → 𝐴 ≠ ∅) |
| Colors of variables: wff setvar class |
| Syntax hints: → wi 4 = wceq 1560 ≠ wne 2957 ∅c0 4285 class class class wbr 5100 suc csuc 6348 ≈ cen 8924 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1815 ax-4 1829 ax-5 1930 ax-6 1987 ax-7 2028 ax-8 2144 ax-9 2152 ax-ext 2734 ax-sep 5246 ax-nul 5256 ax-pr 5390 |
| This theorem depends on definitions: df-bi 209 df-an 400 df-or 859 df-3an 1100 df-tru 1563 df-fal 1573 df-ex 1800 df-sb 2091 df-mo 2566 df-clab 2741 df-cleq 2754 df-clel 2837 df-ne 2958 df-ral 3077 df-rex 3087 df-rab 3415 df-v 3456 df-dif 3907 df-un 3909 df-in 3911 df-ss 3921 df-nul 4286 df-if 4481 df-sn 4583 df-pr 4585 df-op 4589 df-br 5101 df-opab 5163 df-id 5542 df-xp 5653 df-rel 5654 df-cnv 5655 df-co 5656 df-dm 5657 df-rn 5658 df-suc 6352 df-fun 6523 df-fn 6524 df-f 6525 df-f1 6526 df-fo 6527 df-f1o 6528 df-en 8928 |
| This theorem is referenced by: (None) |
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