1 \documentclass[tikz
]{standalone
}
3 \usetikzlibrary{arrows.meta,shapes.symbols,matrix,positioning
}
6 \matrix (tree)
[matrix of nodes,nodes in empty cells, row sep=
1em
] {
8 \texttt{delay
} & &
\verb#>>=.#$~
\lambda$
\verb#x#$
\shortrightarrow$\\
9 &
\texttt{writeD
} & & |
[fill=gray!
15,label=
{[xshift=
1em,label distance=-
5pt
]above:
{\tiny interpreter
}}]|
\verb#blink (Not x)#\\
11 \draw (tree-
1-
2.south) -- (tree-
2-
1.north);
12 \draw (tree-
1-
2.south) -- (tree-
2-
3.north);
13 \draw (tree-
2-
3.south) -- (tree-
3-
2.north);
14 \draw (tree-
2-
3.south) -- (
[xshift=-
1.5em
]tree-
3-
4.north);
15 \draw [->,dashed
] (
[xshift=-
1.5em
]tree-
3-
4.north) to
[out=
25,in=
25] (tree-
1-
2.east);