On 2017-05-07 05:19, Theodore Lief Gannon wrote:

To avoid surprises, they shouldn't propagate -- when foldMap invokes even, it sees the default Monoid instance for Bool (i.e. none).

That sounds like a gateway to inconsistency. I think the solution is that adding an aspect to, say, an Int would not apply that aspects to all Int's, but only to the ones unifying with the annotated one.