User blog comment:B1mb0w/Mapping D(l,0,1) to epsilon nought/@comment-1605058-20150702203134/@comment-10262436-20150702211057

BTW

Thanks for the PDF link. Interesting find.

I am a little surprised something like the D function has not been investigated, so I will read with interest how the paper refers to recursive functions in general.

It may take me a while; I have not read a maths paper since the 20th century :-)