I wonder if it is useful at all. If `f a` already has a Monoid instance, you can use `(<>)` already instead of (<|>) with pretty much the same laws. Plus you don't have to import `(<>)` as it comes from the Prelude where `(<|>)` doesn't. Does this have an use case or is just for aesthetic completeness? -- -- Ruben -- pgp: 4EE9 28F7 932E F4AD