jnr (Just (x', lv')) (x, lv) = if x' > x then Just (x', lv') else Just (x, lv)
jnr (Just (x', lv')) (x, lv) = if x' > x then Just (x', lv') else Just (x, lv)
jnr (Just (x', lv')) (x, lv) = if x' > x then Just (x', lv') else Just (x, lv)