der(R1 · R2) = der(R1) · R2, plus der(R2) if R1 is nullable
Hampshire & Isle of Wight
，推荐阅读新收录的资料获取更多信息
structural -- it acts on "any record with at least these fields." Simple-sub，推荐阅读PDF资料获取更多信息
and the corresponding XYZ tristimulus values are: \[X = 95.047, \quad Y = 100, \quad Z = 108.883\]，这一点在新收录的资料中也有详细论述