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authorFranciszek Malinka <franciszek.malinka@gmail.com>2022-07-09 13:44:59 +0200
committerFranciszek Malinka <franciszek.malinka@gmail.com>2022-07-09 13:44:59 +0200
commite55ffead297fd04fe73e5f7bd6d05a151450fb99 (patch)
tree4a173d26144a7b78ae1fd94ff8f2617d20f9efd9 /sections/fraisse_classes.tex
parentbd01da032991f9671557ef64e23ca684fa6c995a (diff)
Aspelled
Diffstat (limited to 'sections/fraisse_classes.tex')
-rw-r--r--sections/fraisse_classes.tex9
1 files changed, 5 insertions, 4 deletions
diff --git a/sections/fraisse_classes.tex b/sections/fraisse_classes.tex
index 9110f44..dc6392d 100644
--- a/sections/fraisse_classes.tex
+++ b/sections/fraisse_classes.tex
@@ -149,6 +149,7 @@
\end{proof}
\begin{definition}
+ \label{definition:random_graph}
The \emph{random graph} is the Fraïssé limit of the class of finite graphs
$\cG$ denoted by $\FrGr = \Flim(\cG)$.
\end{definition}
@@ -253,7 +254,7 @@
\end{tikzcd}
\end{center}
- We have deliberately omited names for embeddings of $C$. Of course,
+ We have deliberately omitted names for embeddings of $C$. Of course,
the functor has to take them into account, but this abuse of notation
is convenient and should not lead into confusion.
\item Let $A\leftarrow C\rightarrow B$, $A'\leftarrow C\rightarrow B'$ be cospans
@@ -414,13 +415,13 @@
theorem \ref{theorem:fraisse_thm} it suffices to show that the age of $\Pi$
is $\cC$ and that it has the weak ultrahomogeneity in the class $\cC$. The
former comes easily, as for every structure $A\in \cC$ we have the structure
- $(A, \id_A)\in \cD$, which means that the structure $A$ embedds into $\Pi$.
- Also, if a structure $(B, \beta)\in\cD$ embedds into $\cD$, then $B\in\cC$.
+ $(A, \id_A)\in \cD$, which means that the structure $A$ embeds into $\Pi$.
+ Also, if a structure $(B, \beta)\in\cD$ embeds into $\cD$, then $B\in\cC$.
Hence, $\cC$ is indeed the age of $\Pi$.
Now, take any structure $A, B\in\cC$ such that $A\subseteq B$. Without the
loss of generality assume that $A = B\cap \Pi$. Let $\bar{A}$ be the
- smallest structure closed on the automorphism $\sigma$ and containg $A$.
+ smallest structure closed on the automorphism $\sigma$ and containing $A$.
It is finite, as $\cC$ is the age of $\Pi$. By the weak Hrushovski property,
of $\cC$ let $(\bar{B}, \beta)$ be a structure extending
$(B\cup \bar{A}, \sigma\upharpoonright_{\bar{A}})$. Again, we may assume