Tue, 18 Jan 2011 19:27:30 +0100 Christian Urban defined properly substitution
Tue, 18 Jan 2011 18:04:40 +0100 Christian Urban derived stronger Abs_eq_iff2 theorems
(0) -1000 -300 -100 -30 -10 -2 +2 +10 +30 +100 +300 tip