% Instability without Cancelation
% 
% calculate y=\sqrt{\sqrt{ .... \sqrt{x}} ... }} (60 imbeddings) 
% and then, x=(( ... (y^2)^2) ... )^2)^2
% 
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 
format long 
x=10
% First calculate this: 
 for i=1:60
     x=sqrt(x);
 end
% (the result is  \sqrt{\sqrt{ .... \sqrt{x}} ... }} (60 imbeddings)
 x
% then do the inverse calculation: 
 for i=1:60
     x=x*x;
 end
% (the result is (( ... (x^2)^2) ... )^2)^2) 
 x  
% why are we getting some thing different from original x?