Commands and Program States

Command order is determined only by the system’s need to know and do certain things in logical sequence. You cannot label a variable before the variable exists in the file. Similarly, you cannot transform or analyze data before a active dataset is defined. This appendix briefly describes how the program handles various tasks in a logical sequence. It is not necessary to understand the program states in order to construct a command file, but some knowledge of how the program works will help you considerably when you encounter a problem or try to determine why the program doesn’t seem to want to accept your commands or seems to be carrying out your instructions incorrectly.