import Control.Monad
import Data.Maybe
import qualified Data.ByteString.Char8 as BS
import Data.List

readInt = fst . fromJust . BS.readInt
readIntList = map readInt . BS.words
getInt = readInt <$> BS.getLine
getIntList = readIntList <$> BS.getLine

main = do
    [a,b,c,d] <- getIntList
    putStrLn $ if abs (a-c) <= d || (abs (a-b) <= d && abs (b-c) <= d) then "Yes" else "No"