a__first 0 X nil a__first s X cons Y Z cons mark Y first X Z a__from X cons mark X from s X mark first X1 X2 a__first mark X1 mark X2 mark from X a__from mark X mark 0 0 mark nil nil mark s X s mark X mark cons X1 X2 cons mark X1 X2 a__first X1 X2 first X1 X2 a__from X from X a__first 2 0 0 nil 0 s 1 cons 2 mark 1 first 2 a__from 1 from 1 INNERMOST ./TRS/TRCSR/inn/Ex6_Luc98_GM.trs