improved show_brackets again - Trueprop does not create () any more.
improved show_brackets again - Trueprop does not create () any more.

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