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Theorem ndfatafv2 44962
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 44960 . 2 (𝐹''''𝐴) = if(𝐹 defAt 𝐴, (℩𝑥𝐴𝐹𝑥), 𝒫 ran 𝐹)
2 iffalse 4478 . 2 𝐹 defAt 𝐴 → if(𝐹 defAt 𝐴, (℩𝑥𝐴𝐹𝑥), 𝒫 ran 𝐹) = 𝒫 ran 𝐹)
31, 2eqtrid 2789 1 𝐹 defAt 𝐴 → (𝐹''''𝐴) = 𝒫 ran 𝐹)
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4   = wceq 1540  ifcif 4469  𝒫 cpw 4543   cuni 4848   class class class wbr 5085  ran crn 5606  cio 6413   defAt wdfat 44867  ''''cafv2 44959
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 1912  ax-6 1970  ax-7 2010  ax-8 2107  ax-9 2115  ax-ext 2708
This theorem depends on definitions:  df-bi 206  df-an 397  df-or 845  df-ex 1781  df-sb 2067  df-clab 2715  df-cleq 2729  df-clel 2815  df-if 4470  df-afv2 44960
This theorem is referenced by:  ndfatafv2undef  44963  ndfatafv2nrn  44972  afv2ndefb  44975  afv20defat  44983
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