import tensorflow as tf

    :param white: bool
    :return: N x R  or R x N x N
    """
    logger.debug("base conditional")
    # compute kernel stuff
    num_func = tf.shape(f)[1]  # R
    Lm = tf.cholesky(Kmm)

    # Compute the projection matrix A
    A = tf.matrix_triangular_solve(Lm, Kmn, lower=True)
