新组合概型的生成及其性质

Constructions and properties of the new combinatorial schemes

以“秩”的形式给出了偏序集拟阵中限制与收缩两种运算作用相等的一个充要条件,显示了秩函数在研究偏序集拟阵中的重要作用.详细地讨论了产生新组合概型的限制、收缩、截短和延伸等运算,并研究了它们的一些性质.

The necessary and sufficient condition is given to ensure the restriction and contraction to the same subset of a posot matroid processes the same result,which indicates that the rank function plays an important role in the study of poset matroids. And then some oporations on combinatorial schemes are discussed, such as restriction, contraction, truncation and elongation, Some properties of these oporations are also studied.