active fst 0 Z mark nil active fst s X cons Y Z mark cons Y fst X Z active from X mark cons X from s X active add 0 X mark X active add s X Y mark s add X Y active len nil mark 0 active len cons X Z mark s len Z mark fst X1 X2 active fst mark X1 mark X2 mark 0 active 0 mark nil active nil mark s X active s X mark cons X1 X2 active cons mark X1 X2 mark from X active from mark X mark add X1 X2 active add mark X1 mark X2 mark len X active len mark X fst mark X1 X2 fst X1 X2 fst X1 mark X2 fst X1 X2 fst active X1 X2 fst X1 X2 fst X1 active X2 fst X1 X2 s mark X s X s active X s X cons mark X1 X2 cons X1 X2 cons X1 mark X2 cons X1 X2 cons active X1 X2 cons X1 X2 cons X1 active X2 cons X1 X2 from mark X from X from active X from X add mark X1 X2 add X1 X2 add X1 mark X2 add X1 X2 add active X1 X2 add X1 X2 add X1 active X2 add X1 X2 len mark X len X len active X len X active 1 fst 2 0 0 mark 1 nil 0 s 1 cons 2 from 1 add 2 len 1 INNERMOST ./TRS/TRCSR/inn/Ex2_Luc03b_iGM.trs