# Zulip Chat Archive

## Stream: general

### Topic: the apple monad

#### Johan Commelin (Jul 24 2019 at 05:16):

Welcome back @Johannes Hölzl :wave: :apple: :octopus:

#### Johannes Hölzl (Jul 24 2019 at 16:17):

This is not work related.

#### Johannes Hölzl (Jul 24 2019 at 16:18):

It is nice to see that I finally see an application of category theory. I think proving Ionescu Tulcea, i.e. that the Giry monad (on probability measures) allows us to construct Markov processes, can be simplified using some general constructions.

#### Johan Commelin (Jul 24 2019 at 16:32):

This is not work related.

Sure, but it's nevertheless very nice to see this activity (-;

#### Johan Commelin (Jul 24 2019 at 16:32):

And yes, an application of category theory is really nice.

#### Koundinya Vajjha (Jul 24 2019 at 17:49):

It is nice to see that I finally see an application of category theory. I think proving Ionescu Tulcea, i.e. that the Giry monad (on probability measures) allows us to construct Markov processes, can be simplified using some general constructions.

I would like to thank you @Johannes Hölzl for your measure theory library. It has been really spectacular. (I almost wept with delight when I discovered the `induction_on_inter`

version of Dynkin's theorem.)

Last updated: May 13 2021 at 22:15 UTC