I'm not sure resistance to crashing is a good way to think of it? It just means that you need to pass it an int for logical results, and if you do it'll return

I'm not sure resistance to crashing is a good way to think of it? It just means that you need to pass it an int for logical results, and if you do it'll return you an int if everything goes well. The types don't prove the logic doing the right thing or that nothing can break while the function runs, but they prove that you are using it mostly correctly in what you give it and what you do with what it'll return.