Although this is not a default feature of SIC, many programs using SIC call a initialization macro at run time to define symbols, execute startup commands and so on. This file is typically named
GAG_INIT:INIT.DefExt
where DefExt is the default macro extension used by the program, and
is usually the program name. Consult the specific programs documentation.
GAG_INIT is a logical name that normally points to your login
directory.