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Mirrors > Home > MPE Home > Th. List > cardval2 | Structured version Visualization version GIF version |
Description: An alternate version of the value of the cardinal number of a set. Compare cardval 10487. This theorem could be used to give a simpler definition of card in place of df-card 9880. It apparently does not occur in the literature. (Contributed by NM, 7-Nov-2003.) |
Ref | Expression |
---|---|
cardval2 | β’ (π΄ β dom card β (cardβπ΄) = {π₯ β On β£ π₯ βΊ π΄}) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cardon 9885 | . . . . . 6 β’ (cardβπ΄) β On | |
2 | 1 | oneli 6432 | . . . . 5 β’ (π₯ β (cardβπ΄) β π₯ β On) |
3 | 2 | pm4.71ri 562 | . . . 4 β’ (π₯ β (cardβπ΄) β (π₯ β On β§ π₯ β (cardβπ΄))) |
4 | cardsdomel 9915 | . . . . . 6 β’ ((π₯ β On β§ π΄ β dom card) β (π₯ βΊ π΄ β π₯ β (cardβπ΄))) | |
5 | 4 | ancoms 460 | . . . . 5 β’ ((π΄ β dom card β§ π₯ β On) β (π₯ βΊ π΄ β π₯ β (cardβπ΄))) |
6 | 5 | pm5.32da 580 | . . . 4 β’ (π΄ β dom card β ((π₯ β On β§ π₯ βΊ π΄) β (π₯ β On β§ π₯ β (cardβπ΄)))) |
7 | 3, 6 | bitr4id 290 | . . 3 β’ (π΄ β dom card β (π₯ β (cardβπ΄) β (π₯ β On β§ π₯ βΊ π΄))) |
8 | 7 | abbi2dv 2868 | . 2 β’ (π΄ β dom card β (cardβπ΄) = {π₯ β£ (π₯ β On β§ π₯ βΊ π΄)}) |
9 | df-rab 3407 | . 2 β’ {π₯ β On β£ π₯ βΊ π΄} = {π₯ β£ (π₯ β On β§ π₯ βΊ π΄)} | |
10 | 8, 9 | eqtr4di 2791 | 1 β’ (π΄ β dom card β (cardβπ΄) = {π₯ β On β£ π₯ βΊ π΄}) |
Colors of variables: wff setvar class |
Syntax hints: β wi 4 β wb 205 β§ wa 397 = wceq 1542 β wcel 2107 {cab 2710 {crab 3406 class class class wbr 5106 dom cdm 5634 Oncon0 6318 βcfv 6497 βΊ csdm 8885 cardccrd 9876 |
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-10 2138 ax-11 2155 ax-12 2172 ax-ext 2704 ax-sep 5257 ax-nul 5264 ax-pow 5321 ax-pr 5385 ax-un 7673 |
This theorem depends on definitions: df-bi 206 df-an 398 df-or 847 df-3or 1089 df-3an 1090 df-tru 1545 df-fal 1555 df-ex 1783 df-nf 1787 df-sb 2069 df-mo 2535 df-eu 2564 df-clab 2711 df-cleq 2725 df-clel 2811 df-nfc 2886 df-ne 2941 df-ral 3062 df-rex 3071 df-rab 3407 df-v 3446 df-dif 3914 df-un 3916 df-in 3918 df-ss 3928 df-pss 3930 df-nul 4284 df-if 4488 df-pw 4563 df-sn 4588 df-pr 4590 df-op 4594 df-uni 4867 df-int 4909 df-br 5107 df-opab 5169 df-mpt 5190 df-tr 5224 df-id 5532 df-eprel 5538 df-po 5546 df-so 5547 df-fr 5589 df-we 5591 df-xp 5640 df-rel 5641 df-cnv 5642 df-co 5643 df-dm 5644 df-rn 5645 df-res 5646 df-ima 5647 df-ord 6321 df-on 6322 df-iota 6449 df-fun 6499 df-fn 6500 df-f 6501 df-f1 6502 df-fo 6503 df-f1o 6504 df-fv 6505 df-er 8651 df-en 8887 df-dom 8888 df-sdom 8889 df-card 9880 |
This theorem is referenced by: ondomon 10504 alephsuc3 10521 |
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