(iii.2) p = p <=< unit (here p has to be a natural transformation from 1C)
If `p` is a natural transformation from `P` to `M(1C)` and `q` is `(p Q')`, that is, a natural transformation from `PQ` to `MQ`, then we can extend (iii.1) as follows:
(iii.2) p = p <=< unit (here p has to be a natural transformation from 1C)
If `p` is a natural transformation from `P` to `M(1C)` and `q` is `(p Q')`, that is, a natural transformation from `PQ` to `MQ`, then we can extend (iii.1) as follows: