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For questions requesting examples of a certain structure or phenomenon
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answers
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Examples of non-polynomial comonads on Set?
Question: What are examples of comonads on $\mathbf{Set}$ that are not polynomial? … Question:
$\quad$ What are examples of comonads on $\mathbf{Set}$ that are not polynomial? …
6
votes
Big list of comonads
For any monoid $(M,e,*)$ in $\mathsf{Set}$ there is a corresponding comonad $y^M$ on $\mathsf{Set}$. It sends a set $A$ to the set of morphisms into $A$ from $M$,
$$
A\mapsto A^M.
$$
Note that $y=y^1$ …