zeros cons 0 n__zeros and tt X activate X length nil 0 length cons N L s length activate L take 0 IL nil take s M cons N IL cons N n__take M activate IL zeros n__zeros take X1 X2 n__take X1 X2 activate n__zeros zeros activate n__take X1 X2 take X1 X2 activate X X zeros 0 cons 2 0 0 n__zeros 0 and 2 tt 0 activate 1 length 1 nil 0 s 1 take 2 n__take 2 FULL ./TRS/TRCSR/OvConsOS_nosorts_Z.trs