result of erfc is never more precise than double 5 results were exact to double the precision 20 largest ulp errors (stored in a double) 1.55074 ulp for erfc(12.1195662651077818) = 7.50949328584440654e-66) 1.54627 ulp for erfc(12.407681680893587) = 6.25827238210652832e-69) 1.51478 ulp for erfc(1.89519053177917973) = 0.00735772712418380007) 1.50941 ulp for erfc(1.76289650465688319) = 0.0126628844207123756) 1.50854 ulp for erfc(1.58342289088495303) = 0.0251365246572839499) 1.50581 ulp for erfc(10.5952364563678607) = 9.35236524157818037e-51) 1.50387 ulp for erfc(1.21790004349117842) = 0.0850023771511491111) 1.50377 ulp for erfc(13.7514437934095568) = 3.06119641471006947e-84) 1.50343 ulp for erfc(6.34157082491695245) = 3.01029001726367322e-19) 1.50331 ulp for erfc(10.1671825617441094) = 7.05395370005023563e-47) 1.50261 ulp for erfc(14.7064886456213166) = 4.50148931866354397e-96) 1.50196 ulp for erfc(10.2580820608215841) = 1.09212414903953798e-47) 1.50081 ulp for erfc(10.2580820608538001) = 1.09212414831430171e-47) 1.50059 ulp for erfc(4.5064146858337919) = 1.85326270107492819e-10) 1.50056 ulp for erfc(13.2166785083890517) = 5.83783374106980858e-78) 1.50050 ulp for erfc(13.9712777837393123) = 6.79635393052218879e-87) 1.50040 ulp for erfc(4.09194005615514733) = 7.17069916342429865e-09) 1.50023 ulp for erfc(4.09194005618304235) = 7.17069916174097949e-09) 1.50017 ulp for erfc(6.2598240838090522) = 8.54055364435861305e-19) 1.50014 ulp for erfc(3.50777828534097802) = 7.02223792672287551e-07)