[交流] 【求助】一个趣题求助

Originally posted by sxu2009 at 2011-01-02 17:46:21:

不好意思，我表达的不清楚，举个例子：对于B中的任意一个元素(x1,x2)，设f(x1,x2)=(y1,y2)，则（first_x，last_f(x)）表示(x1,y2)。
即原题中加上一个要求“ { (x1, y2) | (x1,x2)属于B 且 (y1,y2)=f(x1, x2 ...

Originally posted by ykwang at 2010-12-11 21:15:50:


[ Last edited by ykwang on 2010-12-11 at 21:28 ]

Originally posted by ykwang at 2010-12-11 21:15:50:


[ Last edited by ykwang on 2010-12-11 at 21:28 ]