 (default value for the C and Ocaml library on
64 bits linux):
<p>

(1) 6.123 233 995 736 765 886 130 329 661 375 001 464 640 377 798 836e-17
<p>

(2) 6.123 031 769 111 885 058 461 925 285 082 049 859 451 216 355 021e-17
<p>

(3) 6.123 031 769 111 886 291 057 089 692 912 995 815 277 099 609 375e-17
<p>

(4) 6.123 031 769 111 886 291 057 089 692 912 995 815 277 099 609 375e-17
<p>

(5) 6.123 233 995 736 766 035 868 820 147 291 983 023 128 460 623 387e-17
<p>

The upper bound (4) computed by the x87 is clearl