Precedence: 8

`yok` - [Y]oneda c[O]variant [K]leisli

How to read: modify argument covariantly with a Kleisli arrow.

It looks similar to yo except the fact that we map a Kleisli morphism - that’s why we have a small hook here.

`yok` : t a `AR_` into (from a (tt o)) (t o)

This operator is useful to do binding:

Some _ `yok` Try `ha` Some `AR__` Some _
None _ `yok` Try `ha` Some `AR__` None _