readArray::IO String -> IO[Int]
readArray = fmap $ map read . words
main = do
    [a,b,c,d] <- readArray getLine
    main = do
    [a,b,c,d] <- readArray getLine
    if abs c-a < d then putStrLn "Yes" else if abs a-b < d && abs c-b < d then putStrLn "Yes" else putStrLn "No"