Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/prelude/List/IsPrefixOf.hs
module List where isPrefixOf :: (Eq a) => [a] -> [a] -> Bool isPrefixOf [] _ = True isPrefixOf (_:_) [] = False isPrefixOf (x:xs) (y:ys) = x == y && isPrefixOf xs ys
