natsFrom N cons N natsFrom s N fst pair XS YS XS snd pair XS YS YS splitAt 0 XS pair nil XS splitAt s N cons X XS u splitAt N XS N X XS u pair YS ZS N X XS pair cons X YS ZS head cons N XS N tail cons N XS XS sel N XS head afterNth N XS take N XS fst splitAt N XS afterNth N XS snd splitAt N XS natsFrom 1 1 cons 2 1 s 1 1 fst 1 1 pair 2 1 2 snd 1 1 splitAt 2 1 2 0 0 nil 0 u 4 1 head 1 1 tail 1 1 sel 2 1 2 afterNth 2 1 2 take 2 1 2 FULL ./TRS/CSR/ExSec4_2_DLMMU04.trs