from X cons X from s X head cons X XS X 2nd cons X XS head XS take 0 XS nil take s N cons X XS cons X take N XS sel 0 cons X XS X sel s N cons X XS sel N XS from 1 cons 2 s 1 head 1 2nd 1 take 2 0 0 nil 0 sel 2 FULL ./TRS/nontermin/CSR/Ex7_BLR02.trs