moved theorem tags from Drule to PureThy;
replaced kind attribute by kind string;
tuned name_multi: index > 1 only;
added note_thmss_qualified (from Isar/locale.ML);
(*<*)
theory fakenat imports Main begin;
(*>*)
text{*\noindent
The type \tydx{nat} of natural
numbers is predefined to have the constructors \cdx{0} and~\cdx{Suc}. It behaves as if it were declared like this:
*}
datatype nat = 0 | Suc nat
(*<*)
end
(*>*)