[M N] res-div K matrix M, N, K ; Each element of M and N must be an element of a ring. coker(K) is isomorphic to M/N. Example: [(x,y) ring_of_differential_operators 0] define_ring [[[(x+x^2+y^2).] [(x y).]] [[(x+x^2+y^2).] [(x y).]]] res-div res*div accepts string inputs, too. For example, [[[[(x+x^2+y^2)] [(x y)]] [[(x+x^2+y^2)] [(x y)]]] [(x) (y)]] res*div :: See also res-toString, res-setRing.