Consider the language F, the set of strings that are syntactically valid Python code for a function requiring no parameters (e.g, def f():...). Observe that F is decidable. Now consider R F, which is the subset of Python code for zero parameter functions, such that execution of the function (e.g., calling f()) throws an exception (of any type).

Show that R is recognizable by explaining how to recognize this language.

Show that R is not decidable by showing an appropriate reduction from a well-known undecidable problem.