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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 9982 | . . 3 ⊢ (card‘𝐴) ∈ On | |
2 | eleq1 2827 | . . 3 ⊢ ((card‘𝐴) = 𝐴 → ((card‘𝐴) ∈ On ↔ 𝐴 ∈ On)) | |
3 | 1, 2 | mpbii 233 | . 2 ⊢ ((card‘𝐴) = 𝐴 → 𝐴 ∈ On) |
4 | cardonle 9995 | . . . 4 ⊢ (𝐴 ∈ On → (card‘𝐴) ⊆ 𝐴) | |
5 | eqss 4011 | . . . . 5 ⊢ ((card‘𝐴) = 𝐴 ↔ ((card‘𝐴) ⊆ 𝐴 ∧ 𝐴 ⊆ (card‘𝐴))) | |
6 | 5 | baibr 536 | . . . 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 | dfss3 3984 | . . . 4 ⊢ (𝐴 ⊆ (card‘𝐴) ↔ ∀𝑥 ∈ 𝐴 𝑥 ∈ (card‘𝐴)) | |
9 | onelon 6411 | . . . . . 6 ⊢ ((𝐴 ∈ On ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ On) | |
10 | onenon 9987 | . . . . . . 7 ⊢ (𝐴 ∈ On → 𝐴 ∈ dom card) | |
11 | 10 | adantr 480 | . . . . . 6 ⊢ ((𝐴 ∈ On ∧ 𝑥 ∈ 𝐴) → 𝐴 ∈ dom card) |
12 | cardsdomel 10012 | . . . . . 6 ⊢ ((𝑥 ∈ On ∧ 𝐴 ∈ dom card) → (𝑥 ≺ 𝐴 ↔ 𝑥 ∈ (card‘𝐴))) | |
13 | 9, 11, 12 | syl2anc 584 | . . . . 5 ⊢ ((𝐴 ∈ On ∧ 𝑥 ∈ 𝐴) → (𝑥 ≺ 𝐴 ↔ 𝑥 ∈ (card‘𝐴))) |
14 | 13 | ralbidva 3174 | . . . 4 ⊢ (𝐴 ∈ On → (∀𝑥 ∈ 𝐴 𝑥 ≺ 𝐴 ↔ ∀𝑥 ∈ 𝐴 𝑥 ∈ (card‘𝐴))) |
15 | 8, 14 | bitr4id 290 | . . 3 ⊢ (𝐴 ∈ On → (𝐴 ⊆ (card‘𝐴) ↔ ∀𝑥 ∈ 𝐴 𝑥 ≺ 𝐴)) |
16 | 7, 15 | bitr3d 281 | . 2 ⊢ (𝐴 ∈ On → ((card‘𝐴) = 𝐴 ↔ ∀𝑥 ∈ 𝐴 𝑥 ≺ 𝐴)) |
17 | 3, 16 | biadanii 822 | 1 ⊢ ((card‘𝐴) = 𝐴 ↔ (𝐴 ∈ On ∧ ∀𝑥 ∈ 𝐴 𝑥 ≺ 𝐴)) |
Colors of variables: wff setvar class |
Syntax hints: ↔ wb 206 ∧ wa 395 = wceq 1537 ∈ wcel 2106 ∀wral 3059 ⊆ wss 3963 class class class wbr 5148 dom cdm 5689 Oncon0 6386 ‘cfv 6563 ≺ csdm 8983 cardccrd 9973 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1792 ax-4 1806 ax-5 1908 ax-6 1965 ax-7 2005 ax-8 2108 ax-9 2116 ax-10 2139 ax-11 2155 ax-12 2175 ax-ext 2706 ax-sep 5302 ax-nul 5312 ax-pow 5371 ax-pr 5438 ax-un 7754 |
This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3or 1087 df-3an 1088 df-tru 1540 df-fal 1550 df-ex 1777 df-nf 1781 df-sb 2063 df-mo 2538 df-eu 2567 df-clab 2713 df-cleq 2727 df-clel 2814 df-nfc 2890 df-ne 2939 df-ral 3060 df-rex 3069 df-rab 3434 df-v 3480 df-dif 3966 df-un 3968 df-in 3970 df-ss 3980 df-pss 3983 df-nul 4340 df-if 4532 df-pw 4607 df-sn 4632 df-pr 4634 df-op 4638 df-uni 4913 df-int 4952 df-br 5149 df-opab 5211 df-mpt 5232 df-tr 5266 df-id 5583 df-eprel 5589 df-po 5597 df-so 5598 df-fr 5641 df-we 5643 df-xp 5695 df-rel 5696 df-cnv 5697 df-co 5698 df-dm 5699 df-rn 5700 df-res 5701 df-ima 5702 df-ord 6389 df-on 6390 df-iota 6516 df-fun 6565 df-fn 6566 df-f 6567 df-f1 6568 df-fo 6569 df-f1o 6570 df-fv 6571 df-er 8744 df-en 8985 df-dom 8986 df-sdom 8987 df-card 9977 |
This theorem is referenced by: cardprclem 10017 cardmin2 10037 infxpenlem 10051 alephsuc2 10118 cardmin 10602 alephreg 10620 pwcfsdom 10621 winalim2 10734 gchina 10737 inar1 10813 r1tskina 10820 gruina 10856 iscard5 43526 |
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