human
Complete this python program:
def _representing_matrices(basis, G, ring):
assistant
#Here is the Python program you requested.

    """Compute the matrices corresponding to the linear maps `m \mapsto
    x_i m` for all variables `x_i`.
    """
    domain = ring.domain
    u = (ring.ngens - 1)
    def var(i):
        return tuple(((([0] * i) + [1]) + ([0] * (u - i))))
    def representing_matrix(m):
        M = [([domain.zero] * len(basis)) for _ in range(len(basis))]
        for (i, v) in enumerate(basis):
            r = ring.term_new(monomial_mul(m, v), domain.one).rem(G)
            for (monom, coeff) in r.terms():
                j = basis.index(monom)
                M[j][i] = coeff
        return M
    return [representing_matrix(var(i)) for i in range((u + 1))]