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Mathbox for Thierry Arnoux |
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Mirrors > Home > MPE Home > Th. List > Mathboxes > ddeval0 | Structured version Visualization version GIF version |
Description: Value of the delta measure. (Contributed by Thierry Arnoux, 14-Sep-2018.) |
Ref | Expression |
---|---|
ddeval0 | ⊢ ((𝐴 ⊆ ℝ ∧ ¬ 0 ∈ 𝐴) → (δ‘𝐴) = 0) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | reex 10479 | . . . . 5 ⊢ ℝ ∈ V | |
2 | 1 | ssex 5121 | . . . 4 ⊢ (𝐴 ⊆ ℝ → 𝐴 ∈ V) |
3 | elpwg 4465 | . . . . 5 ⊢ (𝐴 ∈ V → (𝐴 ∈ 𝒫 ℝ ↔ 𝐴 ⊆ ℝ)) | |
4 | 3 | biimpar 478 | . . . 4 ⊢ ((𝐴 ∈ V ∧ 𝐴 ⊆ ℝ) → 𝐴 ∈ 𝒫 ℝ) |
5 | 2, 4 | mpancom 684 | . . 3 ⊢ (𝐴 ⊆ ℝ → 𝐴 ∈ 𝒫 ℝ) |
6 | eleq2 2871 | . . . . 5 ⊢ (𝑎 = 𝐴 → (0 ∈ 𝑎 ↔ 0 ∈ 𝐴)) | |
7 | 6 | ifbid 4407 | . . . 4 ⊢ (𝑎 = 𝐴 → if(0 ∈ 𝑎, 1, 0) = if(0 ∈ 𝐴, 1, 0)) |
8 | df-dde 31114 | . . . 4 ⊢ δ = (𝑎 ∈ 𝒫 ℝ ↦ if(0 ∈ 𝑎, 1, 0)) | |
9 | 1ex 10488 | . . . . 5 ⊢ 1 ∈ V | |
10 | c0ex 10486 | . . . . 5 ⊢ 0 ∈ V | |
11 | 9, 10 | ifex 4433 | . . . 4 ⊢ if(0 ∈ 𝐴, 1, 0) ∈ V |
12 | 7, 8, 11 | fvmpt 6640 | . . 3 ⊢ (𝐴 ∈ 𝒫 ℝ → (δ‘𝐴) = if(0 ∈ 𝐴, 1, 0)) |
13 | 5, 12 | syl 17 | . 2 ⊢ (𝐴 ⊆ ℝ → (δ‘𝐴) = if(0 ∈ 𝐴, 1, 0)) |
14 | iffalse 4394 | . 2 ⊢ (¬ 0 ∈ 𝐴 → if(0 ∈ 𝐴, 1, 0) = 0) | |
15 | 13, 14 | sylan9eq 2851 | 1 ⊢ ((𝐴 ⊆ ℝ ∧ ¬ 0 ∈ 𝐴) → (δ‘𝐴) = 0) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 396 = wceq 1522 ∈ wcel 2081 Vcvv 3437 ⊆ wss 3863 ifcif 4385 𝒫 cpw 4457 ‘cfv 6230 ℝcr 10387 0cc0 10388 1c1 10389 δcdde 31113 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1777 ax-4 1791 ax-5 1888 ax-6 1947 ax-7 1992 ax-8 2083 ax-9 2091 ax-10 2112 ax-11 2126 ax-12 2141 ax-13 2344 ax-ext 2769 ax-sep 5099 ax-nul 5106 ax-pr 5226 ax-cnex 10444 ax-resscn 10445 ax-1cn 10446 ax-icn 10447 ax-addcl 10448 ax-mulcl 10450 ax-i2m1 10456 |
This theorem depends on definitions: df-bi 208 df-an 397 df-or 843 df-3an 1082 df-tru 1525 df-ex 1762 df-nf 1766 df-sb 2043 df-mo 2576 df-eu 2612 df-clab 2776 df-cleq 2788 df-clel 2863 df-nfc 2935 df-ral 3110 df-rex 3111 df-rab 3114 df-v 3439 df-sbc 3710 df-dif 3866 df-un 3868 df-in 3870 df-ss 3878 df-nul 4216 df-if 4386 df-pw 4459 df-sn 4477 df-pr 4479 df-op 4483 df-uni 4750 df-br 4967 df-opab 5029 df-mpt 5046 df-id 5353 df-xp 5454 df-rel 5455 df-cnv 5456 df-co 5457 df-dm 5458 df-iota 6194 df-fun 6232 df-fv 6238 df-dde 31114 |
This theorem is referenced by: ddemeas 31117 |
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