![]() |
Mathbox for Alexander van der Vekens |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > MPE Home > Th. List > Mathboxes > digfval | Structured version Visualization version GIF version |
Description: Operation to obtain the 𝑘 th digit of a nonnegative real number 𝑟 in the positional system with base 𝐵. (Contributed by AV, 23-May-2020.) |
Ref | Expression |
---|---|
digfval | ⊢ (𝐵 ∈ ℕ → (digit‘𝐵) = (𝑘 ∈ ℤ, 𝑟 ∈ (0[,)+∞) ↦ ((⌊‘((𝐵↑-𝑘) · 𝑟)) mod 𝐵))) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-dig 42188 | . . 3 ⊢ digit = (𝑏 ∈ ℕ ↦ (𝑘 ∈ ℤ, 𝑟 ∈ (0[,)+∞) ↦ ((⌊‘((𝑏↑-𝑘) · 𝑟)) mod 𝑏))) | |
2 | 1 | a1i 11 | . 2 ⊢ (𝐵 ∈ ℕ → digit = (𝑏 ∈ ℕ ↦ (𝑘 ∈ ℤ, 𝑟 ∈ (0[,)+∞) ↦ ((⌊‘((𝑏↑-𝑘) · 𝑟)) mod 𝑏)))) |
3 | oveq1 6556 | . . . . . . 7 ⊢ (𝑏 = 𝐵 → (𝑏↑-𝑘) = (𝐵↑-𝑘)) | |
4 | 3 | oveq1d 6564 | . . . . . 6 ⊢ (𝑏 = 𝐵 → ((𝑏↑-𝑘) · 𝑟) = ((𝐵↑-𝑘) · 𝑟)) |
5 | 4 | fveq2d 6107 | . . . . 5 ⊢ (𝑏 = 𝐵 → (⌊‘((𝑏↑-𝑘) · 𝑟)) = (⌊‘((𝐵↑-𝑘) · 𝑟))) |
6 | id 22 | . . . . 5 ⊢ (𝑏 = 𝐵 → 𝑏 = 𝐵) | |
7 | 5, 6 | oveq12d 6567 | . . . 4 ⊢ (𝑏 = 𝐵 → ((⌊‘((𝑏↑-𝑘) · 𝑟)) mod 𝑏) = ((⌊‘((𝐵↑-𝑘) · 𝑟)) mod 𝐵)) |
8 | 7 | mpt2eq3dv 6619 | . . 3 ⊢ (𝑏 = 𝐵 → (𝑘 ∈ ℤ, 𝑟 ∈ (0[,)+∞) ↦ ((⌊‘((𝑏↑-𝑘) · 𝑟)) mod 𝑏)) = (𝑘 ∈ ℤ, 𝑟 ∈ (0[,)+∞) ↦ ((⌊‘((𝐵↑-𝑘) · 𝑟)) mod 𝐵))) |
9 | 8 | adantl 481 | . 2 ⊢ ((𝐵 ∈ ℕ ∧ 𝑏 = 𝐵) → (𝑘 ∈ ℤ, 𝑟 ∈ (0[,)+∞) ↦ ((⌊‘((𝑏↑-𝑘) · 𝑟)) mod 𝑏)) = (𝑘 ∈ ℤ, 𝑟 ∈ (0[,)+∞) ↦ ((⌊‘((𝐵↑-𝑘) · 𝑟)) mod 𝐵))) |
10 | id 22 | . 2 ⊢ (𝐵 ∈ ℕ → 𝐵 ∈ ℕ) | |
11 | zex 11263 | . . . 4 ⊢ ℤ ∈ V | |
12 | ovex 6577 | . . . 4 ⊢ (0[,)+∞) ∈ V | |
13 | 11, 12 | pm3.2i 470 | . . 3 ⊢ (ℤ ∈ V ∧ (0[,)+∞) ∈ V) |
14 | eqid 2610 | . . . 4 ⊢ (𝑘 ∈ ℤ, 𝑟 ∈ (0[,)+∞) ↦ ((⌊‘((𝐵↑-𝑘) · 𝑟)) mod 𝐵)) = (𝑘 ∈ ℤ, 𝑟 ∈ (0[,)+∞) ↦ ((⌊‘((𝐵↑-𝑘) · 𝑟)) mod 𝐵)) | |
15 | 14 | mpt2exg 7134 | . . 3 ⊢ ((ℤ ∈ V ∧ (0[,)+∞) ∈ V) → (𝑘 ∈ ℤ, 𝑟 ∈ (0[,)+∞) ↦ ((⌊‘((𝐵↑-𝑘) · 𝑟)) mod 𝐵)) ∈ V) |
16 | 13, 15 | mp1i 13 | . 2 ⊢ (𝐵 ∈ ℕ → (𝑘 ∈ ℤ, 𝑟 ∈ (0[,)+∞) ↦ ((⌊‘((𝐵↑-𝑘) · 𝑟)) mod 𝐵)) ∈ V) |
17 | 2, 9, 10, 16 | fvmptd 6197 | 1 ⊢ (𝐵 ∈ ℕ → (digit‘𝐵) = (𝑘 ∈ ℤ, 𝑟 ∈ (0[,)+∞) ↦ ((⌊‘((𝐵↑-𝑘) · 𝑟)) mod 𝐵))) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 383 = wceq 1475 ∈ wcel 1977 Vcvv 3173 ↦ cmpt 4643 ‘cfv 5804 (class class class)co 6549 ↦ cmpt2 6551 0cc0 9815 · cmul 9820 +∞cpnf 9950 -cneg 10146 ℕcn 10897 ℤcz 11254 [,)cico 12048 ⌊cfl 12453 mod cmo 12530 ↑cexp 12722 digitcdig 42187 |
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 |
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-ral 2901 df-rex 2902 df-reu 2903 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-nul 3875 df-if 4037 df-pw 4110 df-sn 4126 df-pr 4128 df-op 4132 df-uni 4373 df-iun 4457 df-br 4584 df-opab 4644 df-mpt 4645 df-id 4953 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-iota 5768 df-fun 5806 df-fn 5807 df-f 5808 df-f1 5809 df-fo 5810 df-f1o 5811 df-fv 5812 df-ov 6552 df-oprab 6553 df-mpt2 6554 df-1st 7059 df-2nd 7060 df-neg 10148 df-z 11255 df-dig 42188 |
This theorem is referenced by: digval 42190 |
Copyright terms: Public domain | W3C validator |