\documentclass[tikz]{standalone}
\usepackage{stmaryrd}
\usetikzlibrary{arrows.meta,shapes.symbols,matrix,positioning}
\begin{document}
\begin{tikzpicture}[node distance=1em]
	\node (s2) {\verb#>>=. \x->#};
	\node (wd) [left=of s2.north,yshift=-3em] {\verb#writeD D3 st#};
	\node (rec) [right=of s2.north,yshift=-3em,fill=gray!15,label={[xshift=1em,label distance=-5pt]above:{\tiny interpreter}}] {\verb#blink (Not x)#};
	\draw (s2.south) -- (wd.north);
	\draw (s2.south) -- ([xshift=-1.5em]rec.north);
%	\draw [->,dashed] ([xshift=-1.5em]rec.north) to [out=25,in=25] (s1.east);
\end{tikzpicture}
\end{document}
