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Mirrors > Home > MPE Home > Th. List > nordeq | Structured version Visualization version GIF version |
Description: A member of an ordinal class is not equal to it. (Contributed by NM, 25-May-1998.) |
Ref | Expression |
---|---|
nordeq | ⊢ ((Ord 𝐴 ∧ 𝐵 ∈ 𝐴) → 𝐴 ≠ 𝐵) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ordirr 6374 | . . . 4 ⊢ (Ord 𝐴 → ¬ 𝐴 ∈ 𝐴) | |
2 | eleq1 2822 | . . . . 5 ⊢ (𝐴 = 𝐵 → (𝐴 ∈ 𝐴 ↔ 𝐵 ∈ 𝐴)) | |
3 | 2 | notbid 318 | . . . 4 ⊢ (𝐴 = 𝐵 → (¬ 𝐴 ∈ 𝐴 ↔ ¬ 𝐵 ∈ 𝐴)) |
4 | 1, 3 | syl5ibcom 244 | . . 3 ⊢ (Ord 𝐴 → (𝐴 = 𝐵 → ¬ 𝐵 ∈ 𝐴)) |
5 | 4 | necon2ad 2956 | . 2 ⊢ (Ord 𝐴 → (𝐵 ∈ 𝐴 → 𝐴 ≠ 𝐵)) |
6 | 5 | imp 408 | 1 ⊢ ((Ord 𝐴 ∧ 𝐵 ∈ 𝐴) → 𝐴 ≠ 𝐵) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 397 = wceq 1542 ∈ wcel 2107 ≠ wne 2941 Ord word 6355 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1798 ax-4 1812 ax-5 1914 ax-6 1972 ax-7 2012 ax-8 2109 ax-9 2117 ax-ext 2704 ax-sep 5295 ax-nul 5302 ax-pr 5423 |
This theorem depends on definitions: df-bi 206 df-an 398 df-or 847 df-3an 1090 df-tru 1545 df-fal 1555 df-ex 1783 df-sb 2069 df-clab 2711 df-cleq 2725 df-clel 2811 df-ne 2942 df-ral 3063 df-rex 3072 df-rab 3434 df-v 3477 df-dif 3949 df-un 3951 df-in 3953 df-ss 3963 df-nul 4321 df-if 4525 df-pw 4600 df-sn 4625 df-pr 4627 df-op 4631 df-br 5145 df-opab 5207 df-eprel 5576 df-fr 5627 df-we 5629 df-ord 6359 |
This theorem is referenced by: php 9198 phplem1OLD 9205 phpOLD 9210 nogt01o 27166 ordtop 35226 limsucncmpi 35235 |
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