
    No. 80-757.
    No. 80-895.
    No. 80-936.
    New York Mercantile Exchange et al. v. Leist et al.; Clayton Brokerage Co. of St. Louis, Inc. v. Leist et al.; and Heinold Commodities, Inc., et al. v. Leist et al.
   C. A. 2d Cir. [Certiorari granted, 450 U. S. 910.] Motions of Futures Industry Association, Inc., New York Stock Exchange, Inc., and Board of Trade of the City of Chicago et al. for leave- to file briefs as amici curiae granted.  