removed eq-polymorphic duplicates; renamed gen_duplicates to duplicates; added is_equal;
removed eq-polymorphic duplicates;
renamed gen_duplicates to duplicates;
added is_equal;

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