请问下面的信息是什么含义？

如果在建模时使用了 MEMBER TENSION 和MEMBER COMPRESSION命令，程序中规定对每一个荷载基本工况必须进行单独分析，MEMBER TENSION（仅受拉构件）命令所定义的构件必须是在每一个CHANGE（改变）命令之后给出的（最后一个除外）。这是因为每一个CHANGE命令表明前一个的MEMBER TENSION命令已被取消。如果需要，必须从新定义MEMBER TENSION。 例如如下的输入是错的： MEMBER TENSION 884 TO 895 900 903 TO 945 LOAD 1 DEAD LOAD MEMBER LOAD 379 380 384 TO 412 425 TO 428 UNI GY -0.12 413 TO 424 437 TO 440 843 846 TO 849 UNI GY -0.06 LOAD 2 LIVE LOAD MEMBER LOAD 379 380 384 TO 412 425 TO 428 433 434 UNI GY -0.44 413 TO 424 437 TO 440 843 846 TO 849 UNI GY -0.22 LOAD 3 EQUIPMENT LOAD MEMBER LOAD 248 TO 259 283 TO 305 328 TO 349 UNI GY -0.26 260 TO 282 306 TO 327 UNI GY -0.17 LOAD 4 WIND LOAD WEST TO EAST JOINT LOAD 107 FX 3.67 25 490 FX 7.41 LOAD 5 WIND LOAD EAST TO WEST JOINT LOAD 110 FX -7.34 111 FX -3.67 PERFORM ANALYSIS STATICS CHECK 下面的输入是正确的： MEMBER TENSION 884 TO 895 900 903 TO 945 LOAD 1 DEAD LOAD MEMBER LOAD 379 380 384 TO 412 425 TO 428 UNI GY -0.12 413 TO 424 437 TO 440 843 846 TO 849 UNI GY -0.06 PERFORM ANALYSIS STATICS CHECK CHANGE LOAD 2 LIVE LOAD MEMBER LOAD 379 380 384 TO 412 425 TO 428 433 434 UNI GY -0.44 413 TO 424 437 TO 440 843 846 TO 849 UNI GY -0.22 PERFORM ANALYSIS STATICS CHECK CHANGE LOAD 3 EQUIPMENT LOAD MEMBER LOAD 248 TO 259 283 TO 305 328 TO 349 UNI GY -0.26 260 TO 282 306 TO 327 UNI GY -0.17 PERFORM ANALYSIS STATICS CHECK CHANGE LOAD 4 WIND LOAD WEST TO EAST JOINT LOAD 107 FX 3.67 25 490 FX 7.41 PERFORM ANALYSIS STATICS CHECK CHANGE LOAD 5 WIND LOAD EAST TO WEST JOINT LOAD 110 FX -7.34 111 FX -3.67 PERFORM ANALYSIS STATICS CHECK CHANGE