function mach( )
%UNTITLED 
format long
x = double(1.)
y = double(2^(-53))%+2^(-55))
z = double(x+y)-x
y1 = double(2^(-53)+2^(-106))
z1 = double(x+y1)-x
y2 = double(2^(-53)+2^(-105))
z2 = double(x+y2)-x
xx = eps
x2 = eps/2
x3 = .501*eps
yy0 = (1+.501*eps)-1
yy1 = (1+xx)-1
yy2 = (1+2*xx)-1
yy3 = (1+2.5*xx)-1
yy4 = (1-.25*eps)-1
end

