rtCharWithBelowB :: BufferM ()
insertCharWithBelowB = maybe (return ()) insertB =<< maybeCharBelowB

in
insertCharWithBelowB :: BufferM ()
insertCharWithBelowB = maybe (return ()) insertB =<< maybeCharBelowB
insertCharWithBelowB = maybe (return ()) insertB =<< maybeCharBelowB