For a singular linear equation Ax = b,x ? R(AD), a small perturbation matrix
E and a vector ?b are given to A and b, respectively. We then have the
perturbed singular linear equation (A+E)~x = b+?b, ~x ? R[(A+E)D]. This
note is devoted to show the minimum property of the condition numbers on the
Drazin inverse AD and the Drazin-inverse solution ADb.