Add missing type signature

1 files changed, 1 insertions, 0 deletions

diff --git a/Alpha.hs b/Alpha.hs
index 5e41649..5d53f71 100644
--- a/Alpha.hs
+++ b/Alpha.hs
@@ -120,6 +120,7 @@ capitalize :: String -> String
 capitalize [] = []
 capitalize str = (Char.toUpper <| List.head str) : (Char.toLower </ List.tail str)
 
+lowercase :: String -> String
 lowercase str = [Char.toLower c | c <- str]
 
 require :: Text -> Maybe a -> a