A set of standard rules and variables are included to facilitate a standard behavior for all of SEP's electronic documents. The standard rules are grouped in a set of files according to their functionality. The most important ones are
An author may choose to include individual files in his makefile. In general, however, an author need only include SEP.top at the top and SEP.bottom at the bottom. These two makefiles, in turn, include all the other standard makefiles. The order of precedence for rules and variables in GNU make is complex Stallman and McGrath (1991). Therefore, we have carefully structured our system of standard include files so that the author of the local application makefile can overwrite any of the included default rules.
Following GNU make recommendations an author should use only lower case letters for the variable names in his makefiles. To avoid conflicts between SEP's standard variables and an author's local variables, we use stricly upper case variable names in the standard makefiles. An author should use lower case letters for his own variable names, reserving upper case to reference or deliberately override one of our supplied standard variables. Unlike some other make dialects, GNU make variables are easy to identify since they are of the form ${variable-name} everywhere except in their definition statements. Therefore, we believe that restricting oneself to lower case variables should be overly constraining.