----- MACE 2.2f, August 2004 ----- The process was started by mccune on gyro.thornwood, Mon Aug 2 15:44:30 2004 The command was "../../bin/mace2 -n4 -m1000". op(400,xfx,*). formula_list(usable). all x y z ((x*y)*z=x* (y*z)). all x y z (x*yyy usable clausifies to: list(usable). 1 [] (x*y)*z=x* (y*z). 2 [] -(x*y