gcd_11

Torbjörn Granlund tg at gmplib.org
Fri Sep 5 19:59:53 UTC 2014


nisse at lysator.liu.se (Niels Möller) writes:

  tg at gmplib.org (Torbjörn Granlund) writes:
  
  > I don't think gcd(0,0) is possible to define.
  
  At least Knuth claims "it is convenient to set gcd(0,0) = 0", TAoCP,
  4.5.2. Then gcd(u, 0) = |u| for *all* integers u. Also PARI/GP seems to
  follow Knuth here. Which doesn't necessarily make that definition
  appropriate in the mpn interface, of course.
  
Curious.  0 is not a divisor and it is not greatest (but smallest)...

(Will reply to the rest later.)

-- 
Torbjörn
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