more defensive representation of forced break within PolyML.PrettyBreak -- avoid accidental blowup if low-level operations are used, notably PolyML.makestring or its variant General.exnMessage;
more defensive representation of forced break within PolyML.PrettyBreak -- avoid accidental blowup if low-level operations are used, notably PolyML.makestring or its variant General.exnMessage;

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