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Mirrors > Home > MPE Home > Th. List > hashbc0 | Structured version Visualization version GIF version |
Description: The set of subsets of size zero is the singleton of the empty set. (Contributed by Mario Carneiro, 22-Apr-2015.) |
Ref | Expression |
---|---|
ramval.c | ⊢ 𝐶 = (𝑎 ∈ V, 𝑖 ∈ ℕ0 ↦ {𝑏 ∈ 𝒫 𝑎 ∣ (♯‘𝑏) = 𝑖}) |
Ref | Expression |
---|---|
hashbc0 | ⊢ (𝐴 ∈ 𝑉 → (𝐴𝐶0) = {∅}) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 0nn0 11900 | . . 3 ⊢ 0 ∈ ℕ0 | |
2 | ramval.c | . . . 4 ⊢ 𝐶 = (𝑎 ∈ V, 𝑖 ∈ ℕ0 ↦ {𝑏 ∈ 𝒫 𝑎 ∣ (♯‘𝑏) = 𝑖}) | |
3 | 2 | hashbcval 16328 | . . 3 ⊢ ((𝐴 ∈ 𝑉 ∧ 0 ∈ ℕ0) → (𝐴𝐶0) = {𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 0}) |
4 | 1, 3 | mpan2 690 | . 2 ⊢ (𝐴 ∈ 𝑉 → (𝐴𝐶0) = {𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 0}) |
5 | hasheq0 13720 | . . . . . . 7 ⊢ (𝑥 ∈ V → ((♯‘𝑥) = 0 ↔ 𝑥 = ∅)) | |
6 | 5 | elv 3446 | . . . . . 6 ⊢ ((♯‘𝑥) = 0 ↔ 𝑥 = ∅) |
7 | 6 | anbi2i 625 | . . . . 5 ⊢ ((𝑥 ∈ 𝒫 𝐴 ∧ (♯‘𝑥) = 0) ↔ (𝑥 ∈ 𝒫 𝐴 ∧ 𝑥 = ∅)) |
8 | id 22 | . . . . . . 7 ⊢ (𝑥 = ∅ → 𝑥 = ∅) | |
9 | 0elpw 5221 | . . . . . . 7 ⊢ ∅ ∈ 𝒫 𝐴 | |
10 | 8, 9 | eqeltrdi 2898 | . . . . . 6 ⊢ (𝑥 = ∅ → 𝑥 ∈ 𝒫 𝐴) |
11 | 10 | pm4.71ri 564 | . . . . 5 ⊢ (𝑥 = ∅ ↔ (𝑥 ∈ 𝒫 𝐴 ∧ 𝑥 = ∅)) |
12 | 7, 11 | bitr4i 281 | . . . 4 ⊢ ((𝑥 ∈ 𝒫 𝐴 ∧ (♯‘𝑥) = 0) ↔ 𝑥 = ∅) |
13 | 12 | abbii 2863 | . . 3 ⊢ {𝑥 ∣ (𝑥 ∈ 𝒫 𝐴 ∧ (♯‘𝑥) = 0)} = {𝑥 ∣ 𝑥 = ∅} |
14 | df-rab 3115 | . . 3 ⊢ {𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 0} = {𝑥 ∣ (𝑥 ∈ 𝒫 𝐴 ∧ (♯‘𝑥) = 0)} | |
15 | df-sn 4526 | . . 3 ⊢ {∅} = {𝑥 ∣ 𝑥 = ∅} | |
16 | 13, 14, 15 | 3eqtr4i 2831 | . 2 ⊢ {𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 0} = {∅} |
17 | 4, 16 | eqtrdi 2849 | 1 ⊢ (𝐴 ∈ 𝑉 → (𝐴𝐶0) = {∅}) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 209 ∧ wa 399 = wceq 1538 ∈ wcel 2111 {cab 2776 {crab 3110 Vcvv 3441 ∅c0 4243 𝒫 cpw 4497 {csn 4525 ‘cfv 6324 (class class class)co 7135 ∈ cmpo 7137 0cc0 10526 ℕ0cn0 11885 ♯chash 13686 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1797 ax-4 1811 ax-5 1911 ax-6 1970 ax-7 2015 ax-8 2113 ax-9 2121 ax-10 2142 ax-11 2158 ax-12 2175 ax-ext 2770 ax-sep 5167 ax-nul 5174 ax-pow 5231 ax-pr 5295 ax-un 7441 ax-cnex 10582 ax-resscn 10583 ax-1cn 10584 ax-icn 10585 ax-addcl 10586 ax-addrcl 10587 ax-mulcl 10588 ax-mulrcl 10589 ax-mulcom 10590 ax-addass 10591 ax-mulass 10592 ax-distr 10593 ax-i2m1 10594 ax-1ne0 10595 ax-1rid 10596 ax-rnegex 10597 ax-rrecex 10598 ax-cnre 10599 ax-pre-lttri 10600 ax-pre-lttrn 10601 ax-pre-ltadd 10602 ax-pre-mulgt0 10603 |
This theorem depends on definitions: df-bi 210 df-an 400 df-or 845 df-3or 1085 df-3an 1086 df-tru 1541 df-ex 1782 df-nf 1786 df-sb 2070 df-mo 2598 df-eu 2629 df-clab 2777 df-cleq 2791 df-clel 2870 df-nfc 2938 df-ne 2988 df-nel 3092 df-ral 3111 df-rex 3112 df-reu 3113 df-rab 3115 df-v 3443 df-sbc 3721 df-csb 3829 df-dif 3884 df-un 3886 df-in 3888 df-ss 3898 df-pss 3900 df-nul 4244 df-if 4426 df-pw 4499 df-sn 4526 df-pr 4528 df-tp 4530 df-op 4532 df-uni 4801 df-int 4839 df-iun 4883 df-br 5031 df-opab 5093 df-mpt 5111 df-tr 5137 df-id 5425 df-eprel 5430 df-po 5438 df-so 5439 df-fr 5478 df-we 5480 df-xp 5525 df-rel 5526 df-cnv 5527 df-co 5528 df-dm 5529 df-rn 5530 df-res 5531 df-ima 5532 df-pred 6116 df-ord 6162 df-on 6163 df-lim 6164 df-suc 6165 df-iota 6283 df-fun 6326 df-fn 6327 df-f 6328 df-f1 6329 df-fo 6330 df-f1o 6331 df-fv 6332 df-riota 7093 df-ov 7138 df-oprab 7139 df-mpo 7140 df-om 7561 df-1st 7671 df-2nd 7672 df-wrecs 7930 df-recs 7991 df-rdg 8029 df-1o 8085 df-er 8272 df-en 8493 df-dom 8494 df-sdom 8495 df-fin 8496 df-card 9352 df-pnf 10666 df-mnf 10667 df-xr 10668 df-ltxr 10669 df-le 10670 df-sub 10861 df-neg 10862 df-nn 11626 df-n0 11886 df-z 11970 df-uz 12232 df-fz 12886 df-hash 13687 |
This theorem is referenced by: 0ram 16346 |
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