active f X mark if X c f true active if true X Y mark X active if false X Y mark Y active f X f active X active if X1 X2 X3 if active X1 X2 X3 active if X1 X2 X3 if X1 active X2 X3 f mark X mark f X if mark X1 X2 X3 mark if X1 X2 X3 if X1 mark X2 X3 mark if X1 X2 X3 proper f X f proper X proper if X1 X2 X3 if proper X1 proper X2 proper X3 proper c ok c proper true ok true proper false ok false f ok X ok f X if ok X1 ok X2 ok X3 ok if X1 X2 X3 top mark X top proper X top ok X top active X active 1 f 1 mark 1 if 3 c 0 true 0 false 0 proper 1 ok 1 top 1 INNERMOST ./TRS/TRCSR/inn/Ex5_Zan97_C.trs