- Explicitely passed pred_subset_eq and pred_equals_eq as an argument to the
to_set and to_pred attributes, because it is no longer applied automatically
- Manually applied predicate1I in proof of accp_subset, because it is no longer
part of the claset
- Replaced psubset_def by less_le
(*<*)
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
(*>*)