function [Q, R] = house(Rt, Qt, n)
	if (nargin == 1)
		[Q, R] = house(Rt, eye(size(Rt)), 1);
	else
		m = size(Rt, 1);
		x = Rt[n:m,n];
		Fx = [norm(x) ; zeros(m-n, 1)];
		v = Fx - x;
		if (n == size(Rt, 2))
		else
		end
	end