Talk:Sudan function

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Please check wether the definition is good. My source isn't a very reliable one (random google search, namely [1]). I hope it's ok, however--it looks enough similarly to the Ackermann function to me to think it grows fast, as it should.

[edit] What is exactly the Sudan function ?

The article does not say what the Sudan function exactly is, as it defines a sequence (F_n)_{n\ge0} of functions.

Perhaps it should be more appropriate to write the function F(n,x,y) whith three arguments. Pierre de Lyon 11:49, 19 May 2006 (UTC)

Would that make the definition:
F(0, x, y) = x+y,\,
F(n+1, x, 0) = x, \ n \ge 0\,
F(n+1, x, y+1) = F(n, F(n+1, x, y), F(n+1, x, y) + y + 1), \ n\ge 0.\,
or shortened:
F(0, x, y) = x+y,\,
F(n, x, 0) = x, \ n \ge 1\,
F(n, x, y) = F(n-1, F(n, x, y-1), F(n, x, y-1) + y), \ n\ge 1.\,
 ? - ℚuackor 20:02, 25 September 2007 (UTC)
This is exactly what I meant. By the way, I prefer the first definition which refers more to its inductive definition and makes a difference between the cases 0 and n + 1. Pierre de Lyon 17:37, 30 October 2007 (UTC)