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Mirrors > Home > MPE Home > Th. List > iscard | Structured version Visualization version GIF version |
Description: Two ways to express the property of being a cardinal number. (Contributed by Mario Carneiro, 15-Jan-2013.) |
Ref | Expression |
---|---|
iscard | ⊢ ((card‘𝐴) = 𝐴 ↔ (𝐴 ∈ On ∧ ∀𝑥 ∈ 𝐴 𝑥 ≺ 𝐴)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cardon 9361 | . . 3 ⊢ (card‘𝐴) ∈ On | |
2 | eleq1 2897 | . . 3 ⊢ ((card‘𝐴) = 𝐴 → ((card‘𝐴) ∈ On ↔ 𝐴 ∈ On)) | |
3 | 1, 2 | mpbii 234 | . 2 ⊢ ((card‘𝐴) = 𝐴 → 𝐴 ∈ On) |
4 | cardonle 9374 | . . . 4 ⊢ (𝐴 ∈ On → (card‘𝐴) ⊆ 𝐴) | |
5 | eqss 3979 | . . . . 5 ⊢ ((card‘𝐴) = 𝐴 ↔ ((card‘𝐴) ⊆ 𝐴 ∧ 𝐴 ⊆ (card‘𝐴))) | |
6 | 5 | baibr 537 | . . . 4 ⊢ ((card‘𝐴) ⊆ 𝐴 → (𝐴 ⊆ (card‘𝐴) ↔ (card‘𝐴) = 𝐴)) |
7 | 4, 6 | syl 17 | . . 3 ⊢ (𝐴 ∈ On → (𝐴 ⊆ (card‘𝐴) ↔ (card‘𝐴) = 𝐴)) |
8 | onelon 6209 | . . . . . 6 ⊢ ((𝐴 ∈ On ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ On) | |
9 | onenon 9366 | . . . . . . 7 ⊢ (𝐴 ∈ On → 𝐴 ∈ dom card) | |
10 | 9 | adantr 481 | . . . . . 6 ⊢ ((𝐴 ∈ On ∧ 𝑥 ∈ 𝐴) → 𝐴 ∈ dom card) |
11 | cardsdomel 9391 | . . . . . 6 ⊢ ((𝑥 ∈ On ∧ 𝐴 ∈ dom card) → (𝑥 ≺ 𝐴 ↔ 𝑥 ∈ (card‘𝐴))) | |
12 | 8, 10, 11 | syl2anc 584 | . . . . 5 ⊢ ((𝐴 ∈ On ∧ 𝑥 ∈ 𝐴) → (𝑥 ≺ 𝐴 ↔ 𝑥 ∈ (card‘𝐴))) |
13 | 12 | ralbidva 3193 | . . . 4 ⊢ (𝐴 ∈ On → (∀𝑥 ∈ 𝐴 𝑥 ≺ 𝐴 ↔ ∀𝑥 ∈ 𝐴 𝑥 ∈ (card‘𝐴))) |
14 | dfss3 3953 | . . . 4 ⊢ (𝐴 ⊆ (card‘𝐴) ↔ ∀𝑥 ∈ 𝐴 𝑥 ∈ (card‘𝐴)) | |
15 | 13, 14 | syl6rbbr 291 | . . 3 ⊢ (𝐴 ∈ On → (𝐴 ⊆ (card‘𝐴) ↔ ∀𝑥 ∈ 𝐴 𝑥 ≺ 𝐴)) |
16 | 7, 15 | bitr3d 282 | . 2 ⊢ (𝐴 ∈ On → ((card‘𝐴) = 𝐴 ↔ ∀𝑥 ∈ 𝐴 𝑥 ≺ 𝐴)) |
17 | 3, 16 | biadanii 818 | 1 ⊢ ((card‘𝐴) = 𝐴 ↔ (𝐴 ∈ On ∧ ∀𝑥 ∈ 𝐴 𝑥 ≺ 𝐴)) |
Colors of variables: wff setvar class |
Syntax hints: ↔ wb 207 ∧ wa 396 = wceq 1528 ∈ wcel 2105 ∀wral 3135 ⊆ wss 3933 class class class wbr 5057 dom cdm 5548 Oncon0 6184 ‘cfv 6348 ≺ csdm 8496 cardccrd 9352 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1787 ax-4 1801 ax-5 1902 ax-6 1961 ax-7 2006 ax-8 2107 ax-9 2115 ax-10 2136 ax-11 2151 ax-12 2167 ax-ext 2790 ax-sep 5194 ax-nul 5201 ax-pow 5257 ax-pr 5320 ax-un 7450 |
This theorem depends on definitions: df-bi 208 df-an 397 df-or 842 df-3or 1080 df-3an 1081 df-tru 1531 df-ex 1772 df-nf 1776 df-sb 2061 df-mo 2615 df-eu 2647 df-clab 2797 df-cleq 2811 df-clel 2890 df-nfc 2960 df-ne 3014 df-ral 3140 df-rex 3141 df-rab 3144 df-v 3494 df-sbc 3770 df-dif 3936 df-un 3938 df-in 3940 df-ss 3949 df-pss 3951 df-nul 4289 df-if 4464 df-pw 4537 df-sn 4558 df-pr 4560 df-tp 4562 df-op 4564 df-uni 4831 df-int 4868 df-br 5058 df-opab 5120 df-mpt 5138 df-tr 5164 df-id 5453 df-eprel 5458 df-po 5467 df-so 5468 df-fr 5507 df-we 5509 df-xp 5554 df-rel 5555 df-cnv 5556 df-co 5557 df-dm 5558 df-rn 5559 df-res 5560 df-ima 5561 df-ord 6187 df-on 6188 df-iota 6307 df-fun 6350 df-fn 6351 df-f 6352 df-f1 6353 df-fo 6354 df-f1o 6355 df-fv 6356 df-er 8278 df-en 8498 df-dom 8499 df-sdom 8500 df-card 9356 |
This theorem is referenced by: cardprclem 9396 cardmin2 9415 infxpenlem 9427 alephsuc2 9494 cardmin 9974 alephreg 9992 pwcfsdom 9993 winalim2 10106 gchina 10109 inar1 10185 r1tskina 10192 gruina 10228 iscard5 39779 |
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