f ** M
M ** f
tensor(f, M)
tensor(M, f)
i1 : R = ZZ/101[x,y];
i2 : R^2 ** vars R o2 = | x y 0 0 | | 0 0 x y | 2 4 o2 : Matrix R <-- R
i3 : (vars R) ** R^2 o3 = | x 0 y 0 | | 0 x 0 y | 2 4 o3 : Matrix R <-- R
When $N$ is a free module of rank 1 the net effect of the operation is to shift the degrees of $f$.
i4 : R = ZZ/101[t];
i5 : f = matrix {{t}} o5 = | t | 1 1 o5 : Matrix R <-- R
i6 : degrees source f o6 = {{1}} o6 : List
i7 : degrees source (f ** R^{-3}) o7 = {{4}} o7 : List