设A={0,1,2,3,4},R={<x,y>|xA,yA且x y<0},S={<x,y>|xA,yA且x y≤3},试求R,S,RS,R-1,S-1,r(R),s(R),t(R),r(S),s(S),t(S). 设A={0,1,2,3,4},R={|xA,yA且x y<0},S={|xA,yA且x y≤3},试求R,S,RS,R-1,S-1,r(R),s(R),t(R),r(S),s(S),t(S). 发布时间:2025-12-08 23:30:35