I have three different matrices, say A(3x6),B(3x6) and C(3x12) with the size of each matrix mentioned within parenthesis. I want to define a fourth matrix D (6x12) so that D=[A,B;C] (in Matlab notation). Can anyone please tell me how to define this D in Maple? Maple help seems not that helpful at least for beginners like me. Thank you in advance.