{-@ .. @-}
hs{-@ safeHead :: { xs:[a] | len xs > 0 } -> a @-} safeHead :: [a] -> a safeHead [] = liquidError "empty list" safeHead (x : _) = x
hs{-@ type Pos = { v:Int | v > 0 } @-}
hs{-@ hoge :: Pos @-} hoge ..