<img src="https://static.zxtiku.com/wangke/imgs/topic/dc342c5e58440328b8d98bbbe934a924.jpg"/><br/> A、sets：<br/> s/1..100/: x;<br/> endsets<br/> @sum(s(i): x(i))<90;<br/> B、 sets:<br/> s/1..100/: x;<br/> endsets<br/> @sum(s : x )<90;<br/> C、 sets:<br/> s/1..100/: x;<br/> endsets<br/> @sum(s(i)|i#le#100: x(i))<90;<br/> D、sets:<br/> s/1..100/: x;<br/> endsets<br/> @sum(s(i)|i#lt#100: x(i))<90;