import std.stdio, std.conv, std.algorithm, std.array, std.math;

void main()
{
  long a, b, c;
  long d;
  readf("%d %d %d %d", &a, &b, &c, &d);

  if ((c-a).abs <= d || (b-a).abs <= d && (c-b).abs <= d) {
    writeln("Yes");
  }
  else {
    writeln("No");
  }
}
