I'm editing some old logic questions created by others at my institution. These question are in-house and not part of the OPL. One of the macros loaded is "logicMacros.pl". In the comments section of the problem is the following.
COMMENT("Logical symbols defined in logicMacros.pl are used in this problem. They can be overwritten by placing a copy of logicMacros.pl in the course directory and modifying the subroutines in that file.");
As far as I can tell, this is pertinent to the command "$neg = negate();" in the set up for the question.
I've tried looking for information about logicMacros.pl and the only reference I can find is in the forums (https://webwork.maa.org/moodle/mod/forum/discuss.php?d=4204) from 2017. Is logicMacros.pl deprecated?
I'm inclined to removed logicMacros.pl from the list of loaded macros as the problems still run. From what I understand, if someone wanted to make some course (or institution?) specific changes, those changes go in PGcourse.pl. In fact, I've noticed some problems in the OPL in Set Theory and Logic/Propositions/Truth Tables also have the command $neg = negate(); in the problem set up and don't load the macro logicMacros.pl. The comment is instead
COMMENT("Logical symbols defined in pg/macros/customizeLaTeX are used in this problem. They can be overwritten by putting new copies of the subroutines PGcourse.pl.");
This second approach seems better.