> Many `Graph` instances are `Monad`s. For example, `Basic` is a `Monad` (and many other things too). But on the other hand `Relation` is not a `Monad`, because it imposes the `Ord` constraint on the underlying type (and Haskell monads are not allowed that).

Indeed, I did say that it was a monad and not a `Monad`; math doesn't suffer from these implementation constraints. :-)

> Thanks, indeed "clique" may be not the best name... I decided to use it, because I would like to reserve "complete graph" to mean something like `clique [1..]` i.e. the complete graph on the whole universe. If we look from this perspective then something like `clique [1..10]` may look like a clique within some bigger graph. Anyway, I admit this may be confusing.

Oh, that makes more sense. Maybe it's worth even making just a throwaway remark to that effect?