Primitive Control sequence definitions.
These represent primitive control sequences that are converted directly to Boxes or Lists containing basic Unicode content, rather than structured XML, or those executed for side effect during digestion in the LaTeXML::Core::Stomach, changing the LaTeXML::Core::State. The results of invoking a LaTeXML::Core::Definition::Primitive, if any, should be a list of digested items (LaTeXML::Core::Box, LaTeXML::Core::List or LaTeXML::Core::Whatsit).
It extends LaTeXML::Core::Definition.
Primitive definitions may have lists of daemon subroutines, beforeDigest and afterDigest, that are executed before (and before the arguments are read) and after digestion. These should either end with return;, (), or return a list of digested objects (LaTeXML::Core::Box, etc) that will be contributed to the current list.