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| Mirrors > Home > MPE Home > Th. List > hashrabrsn | Structured version Visualization version GIF version | ||
| Description: The size of a restricted class abstraction restricted to a singleton is a nonnegative integer. (Contributed by Alexander van der Vekens, 22-Dec-2017.) | 
| Ref | Expression | 
|---|---|
| hashrabrsn | ⊢ (♯‘{𝑥 ∈ {𝐴} ∣ 𝜑}) ∈ ℕ0 | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | eqid 2736 | . 2 ⊢ {𝑥 ∈ {𝐴} ∣ 𝜑} = {𝑥 ∈ {𝐴} ∣ 𝜑} | |
| 2 | rabrsn 4723 | . 2 ⊢ ({𝑥 ∈ {𝐴} ∣ 𝜑} = {𝑥 ∈ {𝐴} ∣ 𝜑} → ({𝑥 ∈ {𝐴} ∣ 𝜑} = ∅ ∨ {𝑥 ∈ {𝐴} ∣ 𝜑} = {𝐴})) | |
| 3 | fveq2 6905 | . . . 4 ⊢ ({𝑥 ∈ {𝐴} ∣ 𝜑} = ∅ → (♯‘{𝑥 ∈ {𝐴} ∣ 𝜑}) = (♯‘∅)) | |
| 4 | hash0 14407 | . . . . 5 ⊢ (♯‘∅) = 0 | |
| 5 | 0nn0 12543 | . . . . 5 ⊢ 0 ∈ ℕ0 | |
| 6 | 4, 5 | eqeltri 2836 | . . . 4 ⊢ (♯‘∅) ∈ ℕ0 | 
| 7 | 3, 6 | eqeltrdi 2848 | . . 3 ⊢ ({𝑥 ∈ {𝐴} ∣ 𝜑} = ∅ → (♯‘{𝑥 ∈ {𝐴} ∣ 𝜑}) ∈ ℕ0) | 
| 8 | fveq2 6905 | . . . 4 ⊢ ({𝑥 ∈ {𝐴} ∣ 𝜑} = {𝐴} → (♯‘{𝑥 ∈ {𝐴} ∣ 𝜑}) = (♯‘{𝐴})) | |
| 9 | hashsng 14409 | . . . . . 6 ⊢ (𝐴 ∈ V → (♯‘{𝐴}) = 1) | |
| 10 | 1nn0 12544 | . . . . . 6 ⊢ 1 ∈ ℕ0 | |
| 11 | 9, 10 | eqeltrdi 2848 | . . . . 5 ⊢ (𝐴 ∈ V → (♯‘{𝐴}) ∈ ℕ0) | 
| 12 | snprc 4716 | . . . . . 6 ⊢ (¬ 𝐴 ∈ V ↔ {𝐴} = ∅) | |
| 13 | fveq2 6905 | . . . . . . 7 ⊢ ({𝐴} = ∅ → (♯‘{𝐴}) = (♯‘∅)) | |
| 14 | 13, 6 | eqeltrdi 2848 | . . . . . 6 ⊢ ({𝐴} = ∅ → (♯‘{𝐴}) ∈ ℕ0) | 
| 15 | 12, 14 | sylbi 217 | . . . . 5 ⊢ (¬ 𝐴 ∈ V → (♯‘{𝐴}) ∈ ℕ0) | 
| 16 | 11, 15 | pm2.61i 182 | . . . 4 ⊢ (♯‘{𝐴}) ∈ ℕ0 | 
| 17 | 8, 16 | eqeltrdi 2848 | . . 3 ⊢ ({𝑥 ∈ {𝐴} ∣ 𝜑} = {𝐴} → (♯‘{𝑥 ∈ {𝐴} ∣ 𝜑}) ∈ ℕ0) | 
| 18 | 7, 17 | jaoi 857 | . 2 ⊢ (({𝑥 ∈ {𝐴} ∣ 𝜑} = ∅ ∨ {𝑥 ∈ {𝐴} ∣ 𝜑} = {𝐴}) → (♯‘{𝑥 ∈ {𝐴} ∣ 𝜑}) ∈ ℕ0) | 
| 19 | 1, 2, 18 | mp2b 10 | 1 ⊢ (♯‘{𝑥 ∈ {𝐴} ∣ 𝜑}) ∈ ℕ0 | 
| Colors of variables: wff setvar class | 
| Syntax hints: ¬ wn 3 ∨ wo 847 = wceq 1539 ∈ wcel 2107 {crab 3435 Vcvv 3479 ∅c0 4332 {csn 4625 ‘cfv 6560 0cc0 11156 1c1 11157 ℕ0cn0 12528 ♯chash 14370 | 
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1794 ax-4 1808 ax-5 1909 ax-6 1966 ax-7 2006 ax-8 2109 ax-9 2117 ax-10 2140 ax-11 2156 ax-12 2176 ax-ext 2707 ax-sep 5295 ax-nul 5305 ax-pow 5364 ax-pr 5431 ax-un 7756 ax-cnex 11212 ax-resscn 11213 ax-1cn 11214 ax-icn 11215 ax-addcl 11216 ax-addrcl 11217 ax-mulcl 11218 ax-mulrcl 11219 ax-mulcom 11220 ax-addass 11221 ax-mulass 11222 ax-distr 11223 ax-i2m1 11224 ax-1ne0 11225 ax-1rid 11226 ax-rnegex 11227 ax-rrecex 11228 ax-cnre 11229 ax-pre-lttri 11230 ax-pre-lttrn 11231 ax-pre-ltadd 11232 ax-pre-mulgt0 11233 | 
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3or 1087 df-3an 1088 df-tru 1542 df-fal 1552 df-ex 1779 df-nf 1783 df-sb 2064 df-mo 2539 df-eu 2568 df-clab 2714 df-cleq 2728 df-clel 2815 df-nfc 2891 df-ne 2940 df-nel 3046 df-ral 3061 df-rex 3070 df-reu 3380 df-rab 3436 df-v 3481 df-sbc 3788 df-csb 3899 df-dif 3953 df-un 3955 df-in 3957 df-ss 3967 df-pss 3970 df-nul 4333 df-if 4525 df-pw 4601 df-sn 4626 df-pr 4628 df-op 4632 df-uni 4907 df-int 4946 df-iun 4992 df-br 5143 df-opab 5205 df-mpt 5225 df-tr 5259 df-id 5577 df-eprel 5583 df-po 5591 df-so 5592 df-fr 5636 df-we 5638 df-xp 5690 df-rel 5691 df-cnv 5692 df-co 5693 df-dm 5694 df-rn 5695 df-res 5696 df-ima 5697 df-pred 6320 df-ord 6386 df-on 6387 df-lim 6388 df-suc 6389 df-iota 6513 df-fun 6562 df-fn 6563 df-f 6564 df-f1 6565 df-fo 6566 df-f1o 6567 df-fv 6568 df-riota 7389 df-ov 7435 df-oprab 7436 df-mpo 7437 df-om 7889 df-1st 8015 df-2nd 8016 df-frecs 8307 df-wrecs 8338 df-recs 8412 df-rdg 8451 df-1o 8507 df-er 8746 df-en 8987 df-dom 8988 df-sdom 8989 df-fin 8990 df-card 9980 df-pnf 11298 df-mnf 11299 df-xr 11300 df-ltxr 11301 df-le 11302 df-sub 11495 df-neg 11496 df-nn 12268 df-n0 12529 df-z 12616 df-uz 12880 df-fz 13549 df-hash 14371 | 
| This theorem is referenced by: (None) | 
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