Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
NCTM or The Math Forum.


Paul
Posts:
733
Registered:
7/12/10


Possible error in Grzegorczyk's seminal paper on Grzegorczyk hierarchy?
Posted:
Jan 8, 2014 8:05 PM


I got stuck very early on when trying to read Some classes of recursive functions, available here: http://matwbn.icm.edu.pl/ksiazki/rm/rm04/rm0401.pdf
On page 4, surely K and L are intended to be functions from the naturals to the naturals.
But, let z = 1001. Then the integral part of sqrt(z) = 31. Square that integral part and we get 961. Hence K(z) = 1001  961 = 40. Hence L(z) = 31  40 = 9. But L(z) should be positive so that we get the promised correspondence between N and N x N.
Is there a typo here, or am I missing something?
Many thanks for your help.
Paul Epstein



