Use ellipses for diagrams

thesis/1-introduction.tex

@@ -388,7 +388,7 @@ Now the \ac{CFG} (\autoref{fig:cfg-non-lexical-lifetimes-branch}) splits up to a
 \begin{figure}[!h]
     \centering
     \begin{tikzpicture}
-        \begin{scope}[every node/.style={draw, rectangle}]
+        \begin{scope}[every node/.style={draw, ellipse}]
             \node (A) at (0,7.5) {\inline{let mut x = 0;}};
             \node[ultra thick] (B) at (0,6) {\inline{let xref = &x;}};
             \node[ultra thick] (C) at (0,4.5) {\inline{if xref != &0 }};