% $Id: Sqrt.oz,v 1.2 2011/10/22 01:26:00 leavens Exp leavens $
declare
fun {Sqrt X}
   % Requires: X > 0.0
   fun {GoodEnough Guess}
      {Abs Guess*Guess - X} < 0.0001
   end
   fun {Improve Guess}
      (Guess+(X/Guess))/2.0  % Newton's method
   end
   fun {SqrtIter Guess}
      if {GoodEnough Guess} then Guess
      else {SqrtIter {Improve Guess}}
      end
   end
in
   {SqrtIter 1.0}
end