On Oct 24, 2005, at 3:32 PM, Aubrey Jaffer wrote:

> ;;;; integer-sqrt attributed to Bradley Lucier by Steve VanDevender.

I didn't invent this method, I got it from

http://www.cs.cmu.edu/afs/cs/project/ai-repository/ai/lang/lisp/code/
math/isqrt/isqrt.txt

as the thread in Google Groups shows.

This method is about half as fast as the method in

   ;; Derived from the paper "Karatsuba Square Root" by Paul Zimmermann,
   ;; INRIA technical report RR-3805, 1999.  (Used in gmp 4.*)

basically because Zimmermann's method's final divide is half the size
of the final divide of the previous method.

Brad