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Mirrors > Home > MPE Home > Th. List > ordirr | Structured version Visualization version GIF version |
Description: No ordinal class is a member of itself. In other words, the membership relation is irreflexive on ordinal classes. Theorem 2.2(i) of [BellMachover] p. 469, generalized to classes. Theorem 1.9(i) of [Schloeder] p. 1. We prove this without invoking the Axiom of Regularity. (Contributed by NM, 2-Jan-1994.) |
Ref | Expression |
---|---|
ordirr | ⊢ (Ord 𝐴 → ¬ 𝐴 ∈ 𝐴) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ordfr 6378 | . 2 ⊢ (Ord 𝐴 → E Fr 𝐴) | |
2 | efrirr 5656 | . 2 ⊢ ( E Fr 𝐴 → ¬ 𝐴 ∈ 𝐴) | |
3 | 1, 2 | syl 17 | 1 ⊢ (Ord 𝐴 → ¬ 𝐴 ∈ 𝐴) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∈ wcel 2104 E cep 5578 Fr wfr 5627 Ord word 6362 |
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 1911 ax-6 1969 ax-7 2009 ax-8 2106 ax-9 2114 ax-ext 2701 ax-sep 5298 ax-nul 5305 ax-pr 5426 |
This theorem depends on definitions: df-bi 206 df-an 395 df-or 844 df-3an 1087 df-tru 1542 df-fal 1552 df-ex 1780 df-sb 2066 df-clab 2708 df-cleq 2722 df-clel 2808 df-ne 2939 df-ral 3060 df-rex 3069 df-rab 3431 df-v 3474 df-dif 3950 df-un 3952 df-in 3954 df-ss 3964 df-nul 4322 df-if 4528 df-pw 4603 df-sn 4628 df-pr 4630 df-op 4634 df-br 5148 df-opab 5210 df-eprel 5579 df-fr 5630 df-we 5632 df-ord 6366 |
This theorem is referenced by: nordeq 6382 ordn2lp 6383 ordtri3or 6395 ordtri1 6396 ordtri3 6399 orddisj 6401 ordunidif 6412 ordnbtwn 6456 onirri 6476 onssneli 6479 epweon 7764 onprc 7767 nlimsucg 7833 nnlim 7871 limom 7873 soseq 8147 smo11 8366 smoord 8367 tfrlem13 8392 omopth2 8586 cofonr 8675 naddcllem 8677 limensuci 9155 infensuc 9157 ordtypelem9 9523 cantnfp1lem3 9677 cantnfp1 9678 oemapvali 9681 tskwe 9947 dif1card 10007 dju1p1e2ALT 10171 nnadju 10194 pwsdompw 10201 cflim2 10260 fin23lem24 10319 fin23lem26 10322 axdc3lem4 10450 ttukeylem7 10512 canthp1lem2 10650 inar1 10772 gruina 10815 grur1 10817 addnidpi 10898 fzennn 13937 hashp1i 14367 noseponlem 27403 noextend 27405 noextenddif 27407 noextendlt 27408 noextendgt 27409 fvnobday 27417 nosepssdm 27425 nosupbnd1lem3 27449 nosupbnd1lem5 27451 nosupbnd2lem1 27454 noinfbnd1lem3 27464 noinfbnd1lem5 27466 noinfbnd2lem1 27469 noetasuplem4 27475 noetainflem4 27479 sucneqond 36549 oaordnrex 42347 omnord1ex 42356 oenord1ex 42367 cantnfresb 42376 tfsconcatb0 42396 nlimsuc 42494 |
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