private static boolean sanityCheck (SubHull lHull, SubHull rHull, Node<Coordinate2D> lPtr, Node<Coordinate2D> rPtr) {
		
		double t = computeSlope(lPtr, rPtr);
		if (lPtr.left != null && computeSlope(lPtr.left, lPtr) < t) {
			return false;
		}
		if (lPtr.right != null && computeSlope(lPtr, lPtr.right) > t) {
			return false;
		}
		if (rPtr.left != null && computeSlope(rPtr.left, rPtr) < t) {
			return false;
		}
		if (rPtr.right != null && computeSlope(rPtr, rPtr.right) > t) {
			return false;
		}
		
		return true;
	}