  This preprint, or a revised version, was never published as it was based on
and included unacknowledged material from Helbig, P. (1997) `The Delta
theta-z_s relation as a cosmological test', first presented at the 12th Potsdam
Cosmology Workshop (V. M"uller, S. Gottl"ober, J.-P. M"ucket & J. Wambsganss
(eds), Singapore: World Scientific, pp. 319--20) and that I wanted this paper,
rather than mine, to receive full credit for the work under discussion. I am
withdrawing my preprint to further emphasize that I take no credit and note
that astro-ph/9804104 by P. Helbig (1998) (MNRAS, 298, 2, 395 (1998)) contains
fully detailed arguments, using the complete JVAS sample and other techniques,
against the claim made by Park & Gott in astro-ph/9702173 (1997) (ApJ, 489,
476).
