replaced NameSpace.append by NameSpace.qualified, which handles empty names as expected; declared intro/elim rules;
replaced NameSpace.append by NameSpace.qualified, which handles empty names as expected;
declared intro/elim rules;

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