public BorelTanner(int k, double mu) throws ParameterException {
		if (k < 1 || mu < 0 || mu > 1) {
			throw new ParameterException("BorelTanner parameters k in N, 0 <= mu <= 1.");
		} else {
			this.k = k;
			this.mu = mu;
			borel = new Borel(mu);
		}
	}