Hi,there: I have a question regarding the operation of matrix. I would like to calculate the summation of two covariance matrixes, Sigmaw and Sigmab and then I would like to calculate the determinant the summation. The symbolic summation matrix is a 6*6 matrix however, Maple can not run it, does that mean maple could not run the summation of 2 matrices? How can I fix it? I very appreciate your help. Gloria Sun