* Isar: preview of problems to finish 'show' now produce an error
* Isar: preview of problems to finish 'show' now produce an error

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