Why are they undefined? IMHO [] would be a perfect answer. Consistent with scanr1 f . drop n = drop n . scanr1 f scanl1 f . take n = take n . scanl1 f and everything else I can imagine. -- __("< Marcin Kowalczyk * [EMAIL PROTECTED] http://qrczak.ids.net.pl/ \__/ GCS/M d- s+:-- a22 C+++$ UL++>++++$ P+++ L++>++++$ E- ^^ W++ N+++ o? K? w(---) O? M- V? PS-- PE++ Y? PGP+ t QRCZAK 5? X- R tv-- b+>++ DI D- G+ e>++++ h! r--%>++ y-