fixed point

from The Free On-line Dictionary of Computing (8 July 2008)

fixed point
fixpoint

   <mathematics> The fixed point of a function, f is any value, x
   for which f x = x.  A function may have any number of fixed
   points from none (e.g. f x = x+1) to infinitely many (e.g. f x
   = x).  The {fixed point combinator}, written as either "fix"
   or "Y" will return the fixed point of a function.

   See also {least fixed point}.

   (1995-04-13)