One thing that is not yet implemented in all detail is intrinsic
procedures. Right now I'm just rejecting all intrinsic procedures in
PROCEDURE statements. But C1212 says:
"If name denotes an intrinsic procedure it shall be one that is listed
in 13.6 and not marked with a bullet (•)."
So, if I want to implement this, how could I distinguish the ones with
a bullet from those without a bullet, other than just manually going
through a list of their names? And are there intrinsic procedures
which are not listed in 13.6?