From 7529edb3027da350671d9295129ee655d0112d55 Mon Sep 17 00:00:00 2001 From: Philip Kaludercic <philip.kaludercic@fau.de> Date: Fri, 22 Mar 2024 15:03:40 +0100 Subject: [PATCH] Add Worwell's theorem --- coalgebra.tex | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/coalgebra.tex b/coalgebra.tex index c8c9602..0df45f0 100644 --- a/coalgebra.tex +++ b/coalgebra.tex @@ -41,6 +41,13 @@ \[ \nu F = \colim_{n < \omega} F^n \terminal. \] \end{definition} +\begin{theorem}[Worwell] + For a \de{finitary} \de{functor} \(F\), + \(\nu F = F^{\omega+\omega}1\), that is to say one extends and + repeats the \(\op{\omega}\)-chain, starting with + \(\nu F = F^\omega\) instead of \(\terminal\). +\end{theorem} + \begin{definition}\label{def:beheqiv} For a \de{endofunctor} \(F : \map{\Set}{\Set}\) and two \fca{} \((C, c)\), \((D, d)\), are \emph{behaviourally equivalent} for -- GitLab