mark_atoms: more precise treatment of SynExt.standard_token_markers vs. syntax consts;
mark_atoms: more precise treatment of SynExt.standard_token_markers vs. syntax consts;

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle