matrix construction.



Hello:
? Does anyone know an easy to do the following with maxima:
?? Given two n-by-n matrices: A and B, create a 2n-by-2n matrix, C, in which A is the upper right submatrix, B is the lower left submatrix, and the other 2 submatrices are all zero?

? Sincerely,
?? John Lawvere