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Theorem ndfatafv2 47248
Description: The alternate function value at a class 𝐴 if the function is not defined at this set 𝐴. (Contributed by AV, 2-Sep-2022.)
Assertion
Ref Expression
ndfatafv2 𝐹 defAt 𝐴 → (𝐹''''𝐴) = 𝒫 ran 𝐹)

Proof of Theorem ndfatafv2
Dummy variable 𝑥 is distinct from all other variables.
StepHypRef Expression
1 df-afv2 47246 . 2 (𝐹''''𝐴) = if(𝐹 defAt 𝐴, (℩𝑥𝐴𝐹𝑥), 𝒫 ran 𝐹)
2 iffalse 4484 . 2 𝐹 defAt 𝐴 → if(𝐹 defAt 𝐴, (℩𝑥𝐴𝐹𝑥), 𝒫 ran 𝐹) = 𝒫 ran 𝐹)
31, 2eqtrid 2778 1 𝐹 defAt 𝐴 → (𝐹''''𝐴) = 𝒫 ran 𝐹)
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4   = wceq 1541  ifcif 4475  𝒫 cpw 4550   cuni 4859   class class class wbr 5091  ran crn 5617  cio 6435   defAt wdfat 47153  ''''cafv2 47245
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1968  ax-7 2009  ax-8 2113  ax-9 2121  ax-ext 2703
This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-ex 1781  df-sb 2068  df-clab 2710  df-cleq 2723  df-clel 2806  df-if 4476  df-afv2 47246
This theorem is referenced by:  ndfatafv2undef  47249  ndfatafv2nrn  47258  afv2ndefb  47261  afv20defat  47269
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