src/Doc/Tutorial/Misc/fakenat.thy
author wenzelm
Thu, 21 Mar 2024 16:28:43 +0100
changeset 79959 6043c3fef052
parent 67406 23307fd33906
child 80914 d97fdabd9e2b
permissions -rw-r--r--
tuned signature: fewer warnings in IntelliJ IDEA;

(*<*)
theory fakenat imports Main begin
(*>*)

text\<open>\noindent
The type \tydx{nat} of natural
numbers is predefined to have the constructors \cdx{0} and~\cdx{Suc}.
It behaves approximately as if it were declared like this:
\<close>

datatype nat = zero ("0") | Suc nat
(*<*)
end
(*>*)