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Mirrors > Home > MPE Home > Th. List > Mathboxes > ensucne0OLD | Structured version Visualization version GIF version |
Description: A class equinumerous to a successor is never empty. (Contributed by RP, 11-Nov-2023.) (Proof modification is discouraged.) (New usage is discouraged.) |
Ref | Expression |
---|---|
ensucne0OLD | ⊢ (𝐴 ≈ suc 𝐵 → 𝐴 ≠ ∅) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | encv 8968 | . . 3 ⊢ (𝐴 ≈ suc 𝐵 → (𝐴 ∈ V ∧ suc 𝐵 ∈ V)) | |
2 | 1 | simprd 494 | . 2 ⊢ (𝐴 ≈ suc 𝐵 → suc 𝐵 ∈ V) |
3 | en0 9034 | . . . . . . 7 ⊢ (𝐴 ≈ ∅ ↔ 𝐴 = ∅) | |
4 | 3 | biimpri 227 | . . . . . 6 ⊢ (𝐴 = ∅ → 𝐴 ≈ ∅) |
5 | 4 | a1i 11 | . . . . 5 ⊢ (suc 𝐵 ∈ V → (𝐴 = ∅ → 𝐴 ≈ ∅)) |
6 | nsuceq0 6447 | . . . . . 6 ⊢ suc 𝐵 ≠ ∅ | |
7 | 0sdomg 9125 | . . . . . 6 ⊢ (suc 𝐵 ∈ V → (∅ ≺ suc 𝐵 ↔ suc 𝐵 ≠ ∅)) | |
8 | 6, 7 | mpbiri 257 | . . . . 5 ⊢ (suc 𝐵 ∈ V → ∅ ≺ suc 𝐵) |
9 | 5, 8 | jctird 525 | . . . 4 ⊢ (suc 𝐵 ∈ V → (𝐴 = ∅ → (𝐴 ≈ ∅ ∧ ∅ ≺ suc 𝐵))) |
10 | ensdomtr 9134 | . . . . 5 ⊢ ((𝐴 ≈ ∅ ∧ ∅ ≺ suc 𝐵) → 𝐴 ≺ suc 𝐵) | |
11 | sdomnen 8998 | . . . . 5 ⊢ (𝐴 ≺ suc 𝐵 → ¬ 𝐴 ≈ suc 𝐵) | |
12 | 10, 11 | syl 17 | . . . 4 ⊢ ((𝐴 ≈ ∅ ∧ ∅ ≺ suc 𝐵) → ¬ 𝐴 ≈ suc 𝐵) |
13 | 9, 12 | syl6 35 | . . 3 ⊢ (suc 𝐵 ∈ V → (𝐴 = ∅ → ¬ 𝐴 ≈ suc 𝐵)) |
14 | 13 | necon2ad 2945 | . 2 ⊢ (suc 𝐵 ∈ V → (𝐴 ≈ suc 𝐵 → 𝐴 ≠ ∅)) |
15 | 2, 14 | mpcom 38 | 1 ⊢ (𝐴 ≈ suc 𝐵 → 𝐴 ≠ ∅) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 394 = wceq 1533 ∈ wcel 2098 ≠ wne 2930 Vcvv 3463 ∅c0 4318 class class class wbr 5143 suc csuc 6366 ≈ cen 8957 ≺ csdm 8959 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1789 ax-4 1803 ax-5 1905 ax-6 1963 ax-7 2003 ax-8 2100 ax-9 2108 ax-10 2129 ax-11 2146 ax-12 2166 ax-ext 2696 ax-sep 5294 ax-nul 5301 ax-pow 5359 ax-pr 5423 ax-un 7737 |
This theorem depends on definitions: df-bi 206 df-an 395 df-or 846 df-3an 1086 df-tru 1536 df-fal 1546 df-ex 1774 df-nf 1778 df-sb 2060 df-mo 2528 df-eu 2557 df-clab 2703 df-cleq 2717 df-clel 2802 df-nfc 2877 df-ne 2931 df-ral 3052 df-rex 3061 df-rab 3420 df-v 3465 df-dif 3943 df-un 3945 df-in 3947 df-ss 3957 df-nul 4319 df-if 4525 df-pw 4600 df-sn 4625 df-pr 4627 df-op 4631 df-uni 4904 df-br 5144 df-opab 5206 df-id 5570 df-xp 5678 df-rel 5679 df-cnv 5680 df-co 5681 df-dm 5682 df-rn 5683 df-res 5684 df-ima 5685 df-suc 6370 df-fun 6544 df-fn 6545 df-f 6546 df-f1 6547 df-fo 6548 df-f1o 6549 df-er 8721 df-en 8961 df-dom 8962 df-sdom 8963 |
This theorem is referenced by: (None) |
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