Thu, 04 Dec 1997 12:50:02 +0100 nipkow pred -> -1
Thu, 04 Dec 1997 12:44:37 +0100 nipkow pred n -> n-1
(0) -3000 -1000 -300 -100 -30 -10 -2 +2 +10 +30 +100 +300 +1000 +3000 +10000 +30000 tip