% or - parallel sink combinator
function s=or(s1,s2), 
	c1=1:channels(s1);
	c2=channels(s1) + (1:channels(s2));
	s=sinkbinop(@vertsplit,@plus,s1,s2);
	function [y1,y2]=vertsplit(x)
		y1=x(c1,:);
		y2=x(c2,:);
	end
end

