import Control.Applicative ((<$>))

main :: IO ()
main = solve <$> map read <$> words <$> getLine >>= putStrLn

solve :: [Int] -> String
solve [a, b, c, d] | abs (a - c) <= d || abs (a - b) <= d && abs (b - c) <= d = "Yes"
                   | otherwise = "No"
