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Mirrors > Home > MPE Home > Th. List > hashpw | Structured version Visualization version GIF version |
Description: The size of the power set of a finite set is 2 raised to the power of the size of the set. (Contributed by Paul Chapman, 30-Nov-2012.) (Proof shortened by Mario Carneiro, 5-Aug-2014.) |
Ref | Expression |
---|---|
hashpw | ⊢ (𝐴 ∈ Fin → (#‘𝒫 𝐴) = (2↑(#‘𝐴))) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pweq 4111 | . . . 4 ⊢ (𝑥 = 𝐴 → 𝒫 𝑥 = 𝒫 𝐴) | |
2 | 1 | fveq2d 6107 | . . 3 ⊢ (𝑥 = 𝐴 → (#‘𝒫 𝑥) = (#‘𝒫 𝐴)) |
3 | fveq2 6103 | . . . 4 ⊢ (𝑥 = 𝐴 → (#‘𝑥) = (#‘𝐴)) | |
4 | 3 | oveq2d 6565 | . . 3 ⊢ (𝑥 = 𝐴 → (2↑(#‘𝑥)) = (2↑(#‘𝐴))) |
5 | 2, 4 | eqeq12d 2625 | . 2 ⊢ (𝑥 = 𝐴 → ((#‘𝒫 𝑥) = (2↑(#‘𝑥)) ↔ (#‘𝒫 𝐴) = (2↑(#‘𝐴)))) |
6 | vex 3176 | . . . . 5 ⊢ 𝑥 ∈ V | |
7 | 6 | pw2en 7952 | . . . 4 ⊢ 𝒫 𝑥 ≈ (2𝑜 ↑𝑚 𝑥) |
8 | pwfi 8144 | . . . . . 6 ⊢ (𝑥 ∈ Fin ↔ 𝒫 𝑥 ∈ Fin) | |
9 | 8 | biimpi 205 | . . . . 5 ⊢ (𝑥 ∈ Fin → 𝒫 𝑥 ∈ Fin) |
10 | df2o2 7461 | . . . . . . 7 ⊢ 2𝑜 = {∅, {∅}} | |
11 | prfi 8120 | . . . . . . 7 ⊢ {∅, {∅}} ∈ Fin | |
12 | 10, 11 | eqeltri 2684 | . . . . . 6 ⊢ 2𝑜 ∈ Fin |
13 | mapfi 8145 | . . . . . 6 ⊢ ((2𝑜 ∈ Fin ∧ 𝑥 ∈ Fin) → (2𝑜 ↑𝑚 𝑥) ∈ Fin) | |
14 | 12, 13 | mpan 702 | . . . . 5 ⊢ (𝑥 ∈ Fin → (2𝑜 ↑𝑚 𝑥) ∈ Fin) |
15 | hashen 12997 | . . . . 5 ⊢ ((𝒫 𝑥 ∈ Fin ∧ (2𝑜 ↑𝑚 𝑥) ∈ Fin) → ((#‘𝒫 𝑥) = (#‘(2𝑜 ↑𝑚 𝑥)) ↔ 𝒫 𝑥 ≈ (2𝑜 ↑𝑚 𝑥))) | |
16 | 9, 14, 15 | syl2anc 691 | . . . 4 ⊢ (𝑥 ∈ Fin → ((#‘𝒫 𝑥) = (#‘(2𝑜 ↑𝑚 𝑥)) ↔ 𝒫 𝑥 ≈ (2𝑜 ↑𝑚 𝑥))) |
17 | 7, 16 | mpbiri 247 | . . 3 ⊢ (𝑥 ∈ Fin → (#‘𝒫 𝑥) = (#‘(2𝑜 ↑𝑚 𝑥))) |
18 | hashmap 13082 | . . . . 5 ⊢ ((2𝑜 ∈ Fin ∧ 𝑥 ∈ Fin) → (#‘(2𝑜 ↑𝑚 𝑥)) = ((#‘2𝑜)↑(#‘𝑥))) | |
19 | 12, 18 | mpan 702 | . . . 4 ⊢ (𝑥 ∈ Fin → (#‘(2𝑜 ↑𝑚 𝑥)) = ((#‘2𝑜)↑(#‘𝑥))) |
20 | hash2 13054 | . . . . 5 ⊢ (#‘2𝑜) = 2 | |
21 | 20 | oveq1i 6559 | . . . 4 ⊢ ((#‘2𝑜)↑(#‘𝑥)) = (2↑(#‘𝑥)) |
22 | 19, 21 | syl6eq 2660 | . . 3 ⊢ (𝑥 ∈ Fin → (#‘(2𝑜 ↑𝑚 𝑥)) = (2↑(#‘𝑥))) |
23 | 17, 22 | eqtrd 2644 | . 2 ⊢ (𝑥 ∈ Fin → (#‘𝒫 𝑥) = (2↑(#‘𝑥))) |
24 | 5, 23 | vtoclga 3245 | 1 ⊢ (𝐴 ∈ Fin → (#‘𝒫 𝐴) = (2↑(#‘𝐴))) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 195 = wceq 1475 ∈ wcel 1977 ∅c0 3874 𝒫 cpw 4108 {csn 4125 {cpr 4127 class class class wbr 4583 ‘cfv 5804 (class class class)co 6549 2𝑜c2o 7441 ↑𝑚 cmap 7744 ≈ cen 7838 Fincfn 7841 2c2 10947 ↑cexp 12722 #chash 12979 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1713 ax-4 1728 ax-5 1827 ax-6 1875 ax-7 1922 ax-8 1979 ax-9 1986 ax-10 2006 ax-11 2021 ax-12 2034 ax-13 2234 ax-ext 2590 ax-rep 4699 ax-sep 4709 ax-nul 4717 ax-pow 4769 ax-pr 4833 ax-un 6847 ax-cnex 9871 ax-resscn 9872 ax-1cn 9873 ax-icn 9874 ax-addcl 9875 ax-addrcl 9876 ax-mulcl 9877 ax-mulrcl 9878 ax-mulcom 9879 ax-addass 9880 ax-mulass 9881 ax-distr 9882 ax-i2m1 9883 ax-1ne0 9884 ax-1rid 9885 ax-rnegex 9886 ax-rrecex 9887 ax-cnre 9888 ax-pre-lttri 9889 ax-pre-lttrn 9890 ax-pre-ltadd 9891 ax-pre-mulgt0 9892 |
This theorem depends on definitions: df-bi 196 df-or 384 df-an 385 df-3or 1032 df-3an 1033 df-tru 1478 df-ex 1696 df-nf 1701 df-sb 1868 df-eu 2462 df-mo 2463 df-clab 2597 df-cleq 2603 df-clel 2606 df-nfc 2740 df-ne 2782 df-nel 2783 df-ral 2901 df-rex 2902 df-reu 2903 df-rmo 2904 df-rab 2905 df-v 3175 df-sbc 3403 df-csb 3500 df-dif 3543 df-un 3545 df-in 3547 df-ss 3554 df-pss 3556 df-nul 3875 df-if 4037 df-pw 4110 df-sn 4126 df-pr 4128 df-tp 4130 df-op 4132 df-uni 4373 df-int 4411 df-iun 4457 df-br 4584 df-opab 4644 df-mpt 4645 df-tr 4681 df-eprel 4949 df-id 4953 df-po 4959 df-so 4960 df-fr 4997 df-we 4999 df-xp 5044 df-rel 5045 df-cnv 5046 df-co 5047 df-dm 5048 df-rn 5049 df-res 5050 df-ima 5051 df-pred 5597 df-ord 5643 df-on 5644 df-lim 5645 df-suc 5646 df-iota 5768 df-fun 5806 df-fn 5807 df-f 5808 df-f1 5809 df-fo 5810 df-f1o 5811 df-fv 5812 df-riota 6511 df-ov 6552 df-oprab 6553 df-mpt2 6554 df-om 6958 df-1st 7059 df-2nd 7060 df-wrecs 7294 df-recs 7355 df-rdg 7393 df-1o 7447 df-2o 7448 df-oadd 7451 df-er 7629 df-map 7746 df-pm 7747 df-en 7842 df-dom 7843 df-sdom 7844 df-fin 7845 df-card 8648 df-cda 8873 df-pnf 9955 df-mnf 9956 df-xr 9957 df-ltxr 9958 df-le 9959 df-sub 10147 df-neg 10148 df-nn 10898 df-2 10956 df-n0 11170 df-z 11255 df-uz 11564 df-fz 12198 df-seq 12664 df-exp 12723 df-hash 12980 |
This theorem is referenced by: ackbijnn 14399 |
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