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Theorem indval 29854
Description: Value of the indicator function generator for a set 𝐴 and a domain 𝑂. (Contributed by Thierry Arnoux, 2-Feb-2017.)
Assertion
Ref Expression
indval ((𝑂𝑉𝐴𝑂) → ((𝟭‘𝑂)‘𝐴) = (𝑥𝑂 ↦ if(𝑥𝐴, 1, 0)))
Distinct variable groups:   𝑥,𝑂   𝑥,𝐴
Allowed substitution hint:   𝑉(𝑥)

Proof of Theorem indval
Dummy variable 𝑎 is distinct from all other variables.
StepHypRef Expression
1 indv 29853 . . 3 (𝑂𝑉 → (𝟭‘𝑂) = (𝑎 ∈ 𝒫 𝑂 ↦ (𝑥𝑂 ↦ if(𝑥𝑎, 1, 0))))
21adantr 481 . 2 ((𝑂𝑉𝐴𝑂) → (𝟭‘𝑂) = (𝑎 ∈ 𝒫 𝑂 ↦ (𝑥𝑂 ↦ if(𝑥𝑎, 1, 0))))
3 eleq2 2687 . . . . 5 (𝑎 = 𝐴 → (𝑥𝑎𝑥𝐴))
43ifbid 4080 . . . 4 (𝑎 = 𝐴 → if(𝑥𝑎, 1, 0) = if(𝑥𝐴, 1, 0))
54mpteq2dv 4705 . . 3 (𝑎 = 𝐴 → (𝑥𝑂 ↦ if(𝑥𝑎, 1, 0)) = (𝑥𝑂 ↦ if(𝑥𝐴, 1, 0)))
65adantl 482 . 2 (((𝑂𝑉𝐴𝑂) ∧ 𝑎 = 𝐴) → (𝑥𝑂 ↦ if(𝑥𝑎, 1, 0)) = (𝑥𝑂 ↦ if(𝑥𝐴, 1, 0)))
7 simpr 477 . . 3 ((𝑂𝑉𝐴𝑂) → 𝐴𝑂)
8 ssexg 4764 . . . . 5 ((𝐴𝑂𝑂𝑉) → 𝐴 ∈ V)
98ancoms 469 . . . 4 ((𝑂𝑉𝐴𝑂) → 𝐴 ∈ V)
10 elpwg 4138 . . . 4 (𝐴 ∈ V → (𝐴 ∈ 𝒫 𝑂𝐴𝑂))
119, 10syl 17 . . 3 ((𝑂𝑉𝐴𝑂) → (𝐴 ∈ 𝒫 𝑂𝐴𝑂))
127, 11mpbird 247 . 2 ((𝑂𝑉𝐴𝑂) → 𝐴 ∈ 𝒫 𝑂)
13 mptexg 6438 . . 3 (𝑂𝑉 → (𝑥𝑂 ↦ if(𝑥𝐴, 1, 0)) ∈ V)
1413adantr 481 . 2 ((𝑂𝑉𝐴𝑂) → (𝑥𝑂 ↦ if(𝑥𝐴, 1, 0)) ∈ V)
152, 6, 12, 14fvmptd 6245 1 ((𝑂𝑉𝐴𝑂) → ((𝟭‘𝑂)‘𝐴) = (𝑥𝑂 ↦ if(𝑥𝐴, 1, 0)))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 196  wa 384   = wceq 1480  wcel 1987  Vcvv 3186  wss 3555  ifcif 4058  𝒫 cpw 4130  cmpt 4673  cfv 5847  0cc0 9880  1c1 9881  𝟭cind 29851
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1719  ax-4 1734  ax-5 1836  ax-6 1885  ax-7 1932  ax-9 1996  ax-10 2016  ax-11 2031  ax-12 2044  ax-13 2245  ax-ext 2601  ax-rep 4731  ax-sep 4741  ax-nul 4749  ax-pow 4803  ax-pr 4867
This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3an 1038  df-tru 1483  df-ex 1702  df-nf 1707  df-sb 1878  df-eu 2473  df-mo 2474  df-clab 2608  df-cleq 2614  df-clel 2617  df-nfc 2750  df-ne 2791  df-ral 2912  df-rex 2913  df-reu 2914  df-rab 2916  df-v 3188  df-sbc 3418  df-csb 3515  df-dif 3558  df-un 3560  df-in 3562  df-ss 3569  df-nul 3892  df-if 4059  df-pw 4132  df-sn 4149  df-pr 4151  df-op 4155  df-uni 4403  df-iun 4487  df-br 4614  df-opab 4674  df-mpt 4675  df-id 4989  df-xp 5080  df-rel 5081  df-cnv 5082  df-co 5083  df-dm 5084  df-rn 5085  df-res 5086  df-ima 5087  df-iota 5810  df-fun 5849  df-fn 5850  df-f 5851  df-f1 5852  df-fo 5853  df-f1o 5854  df-fv 5855  df-ind 29852
This theorem is referenced by:  indval2  29855  indf  29856  indfval  29857
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