A matrix expression is:
+
-
*
Example:
ring r=0,(x,y),dp; poly f= x3y2 + 2x2y2 +2; matrix H = jacob(jacob(f)); // the Hessian of f matrix mc = coef(f,y); print(mc); ==> y2, 1, ==> x3+2x2,2 module MD = [x+y,1,x],[x+y,0,y]; matrix M = MD; print(M); ==> x+y,x+y, ==> 1, 0, ==> x, y