active f X X mark f a b active b mark a mark f X1 X2 active f mark X1 X2 mark a active a mark b active b f mark X1 X2 f X1 X2 f X1 mark X2 f X1 X2 f active X1 X2 f X1 X2 f X1 active X2 f X1 X2 active 1 f 2 mark 1 a 0 b 0 INNERMOST ./TRS/TRCSR/inn/Ex16_Luc06_iGM.trs