function [ d, Ryy, Ryyc ] = verif( x, h )
%VERIF( x, h ) returns the sum of the absolute differences between Ryy and
%Rxx*Rhh where y = x*h.
y = conv(x, h);
Ryy = conv(y, fliplr(y));
Rxx = conv(x, fliplr(x));
Rhh = conv(h, fliplr(h));
Ryyc = conv(Rxx, Rhh);
d = sum(abs(Ryy-Ryyc));