R的传递闭包t(R)=R∪R^2∪R^3∪R^4R={(a,b)(b,a)(b,c)(c,d)}R^2={(a,a)(a,c)(b,b)(b,d)}R^3={(a,b)(a,d)(b,a)}R^4={(a,a)(b,b)}所以t(R)={(a,a)(a,b)(a,c)(a,d)(b,a)(b,b)(b,d)(c,d)}分别求出R的1到n次方 再求并集n...