use proper intr_names (for required case_names);
store con_defs, case_eqns, recursor_eqns, free_iffs, free_elims;
(*<*)
theory fakenat = Main:;
(*>*)
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
(*>*)