This is an inbuilt function function provided by PPWIZARD.
This function is basically a front end for the standard rexx "symbol()" routine which also ensures that the name you passed is valid as a rexx symbol.
The routine causes processing to abort if the passed rexx variable is invalid (this validation is the main purpose of this routine!), if this is not desired then you need to use "symbol()'.
If you know need to know whether or not the value of a rexx variable is valid then this routine could save you hours of debugging only to find that for some stupid reason the value you were using contains one or more invalid characters.
PPWIZARD symbols can be deleted using the #undef command, in a similar manner rexx variables can be removed using the standard rexx 'drop' command.
The function takes a single parameter which is the name of the rexx variable.
The routine returns either '0' (not defined) or '1' for defined.