##
DB<16> p ($expected - $premium)
-2.22044604925031e-16
####
DB<13> $pa = 1.98
DB<14> $pb = 1.98
DB<15> p ($pb == $pb)
1
DB<17> p ($pb - $pa)
0
DB<18>
DB<22> $exp = sprintf("%.8f", $expected)
DB<23> $pre = sprintf("%.8f", $premium)
DB<24> p ($pre - $exp)
0