(I)Halliday d, Resnick r, Krane K Physics 5th ed. John Wiley Sons, 2002 (2)Ford K w. Classical and Modern Physics. Xerox College publishing, 1972 (3)Alonso M, Finn E J. Fundamental
Color Atlas of Pharmacology 2nd edition, revised and expanded Heinz Lüllmann, M. D. Professor Emeritus Department of Pharmacology University of Kiel Germany Klaus Mohr, M. D. Professor Department of Pharmacology and Toxicology Institute of Pharmacy University of Bonn Germany Albrecht Ziegler, Ph. D. Professor Department of Pharmacology University of Kiel Germany Detlef Bieger, M. D. Professor Division of Basic Medical Sciences Faculty of Medicine Memorial University of Newfoundland St. John’s, Newfoundland Canada 164 color plates by Jürgen Wirth
4. 广义笛卡尔积 (Extended Cartesian Product Extended Cartesian Product) z R – n目关系,k1个元组 z S – m目关系,k2个元组 z R×S – 列:(n+m)列的元组的集合 z 元组的前n列是关系R的一个元组 z 后m列是关系S的一个元组 – 行:k1×k2个元组