DBL_EPSILON        49 missing/nextafter.c         d = DBL_EPSILON/2;
DBL_EPSILON        56 missing/nextafter.c         d = -DBL_EPSILON/2;
DBL_EPSILON        59 numeric.c      #ifndef DBL_EPSILON
DBL_EPSILON      2199 numeric.c          const double epsilon = DBL_EPSILON;
DBL_EPSILON      5164 numeric.c          rb_define_const(rb_cFloat, "EPSILON", DBL2NUM(DBL_EPSILON));