import Data.List

main :: IO ()
main = do
    [a,b,c,d] <- map read . words <$> getLine
    putStrLn $ colorfulTransceivers a b c d

colorfulTransceivers :: Int -> Int -> Int -> Int -> String
colorfulTransceivers a b c d = 
    if ( abs(a-c) <= d || abs (a-b) <= d && abs(b-c) <= d)
        then "Yes"
        else "No"
    where