program test
	implicit none
	integer a, b, c, d
	read *, a, b, c, d
	if (abs(c-a)<= d) then
		print '(A)', "Yes"
	else if (abs(b-a) > d) then
		print '(A)', "No"
	else if (abs(b-c) > d) then
		print '(A)', "No"
	else
		print '(A)', "Yes"
	end if
end program test