Thu, 26 Nov 1998 12:18:51 +0100 nipkow Added a general refutation tactic which works by putting things into nnf first.
(0) -3000 -1000 -300 -100 -30 -10 -1 +1 +10 +30 +100 +300 +1000 +3000 +10000 +30000 tip