where each ( ) ∈ , 1 ≤ ≤ , and is arbitrary. For convenience, define (0 0) = (0 0) and (+1 +1) = (1 1). Define such a point sequence to be an up/right path if, for any ≥ 1, we have −1 ≤ and −1 ≤ . Hence an up/right path joins points of in a continuous, piecewise linear manner with line segments of slope , 0 ≤ ≤ ∞, attaching (−1 −1) and ( ) for al...