dbl 0 0 dbl s X s s dbl X dbls nil nil dbls cons X Y cons dbl X dbls Y sel 0 cons X Y X sel s X cons Y Z sel X Z indx nil X nil indx cons X Y Z cons sel X Z indx Y Z from X cons X from s X dbl 1 1 0 0 s 1 dbls 1 1 nil 0 cons 2 sel 2 1 2 indx 2 1 from 1 FULL ./TRS/CSR/Ex3_2_Luc97.trs