import tensorflow as tf

    eKff = expectation(pXnew, kern)  # N (psi0)
    eKuffu = expectation(pXnew, (kern, feat), (kern, feat))  # N x M x M (psi2)
    Luu_tiled = tf.tile(Luu[None, :, :], [num_data, 1, 1])  # remove this line, once issue 216 is fixed
    Li_eKuffu = tf.matrix_triangular_solve(Luu_tiled, eKuffu, lower=True)
