Mon, 09 Nov 1998 15:33:32 +0100 wenzelm Histories of proof states, with undo / redo and prev / back.
(0) -3000 -1000 -300 -100 -30 -10 -1 +1 +10 +30 +100 +300 +1000 +3000 +10000 +30000 tip