i1 : R = QQ[a..d];
i2 : diagonalMatrix vars R o2 = | a 0 0 0 | | 0 b 0 0 | | 0 0 c 0 | | 0 0 0 d | 4 4 o2 : Matrix R <--- R
i3 : diagonalMatrix matrix{{0,2},{4,6}} o3 = | 0 0 0 0 | | 0 4 0 0 | | 0 0 2 0 | | 0 0 0 6 | 4 4 o3 : Matrix ZZ <--- ZZ