This is a math problem, not a tool for learning Haskell. It misleads students because the idiomatic Haskell solution works fine for the small tests provided but falls apart on the massive integers tested when submitting.

I agree, thanks for fixing my Object.create call, schyzoo

This really shouldn't pass if the returned instance isn't actually an instance of a Singleton, i.e. passes an "obj instanceof Singleton" test.

Add more descriptive test errors, like printing the comment above each test case as the test case message.