inp = require('fs').readFileSync('/dev/stdin', 'utf8').split('\n')
l = inp.shift().split(' ')
A = l[0] * 1
B = l[1] * 1
C = l[2] * 1
D = l[3] * 1
console.log(Math.abs(C - A) <= D || (Math.abs(B - A) <= D && Math.abs(C - B) <= D) ? 'Yes' : 'No')