\documentclass{article}

\usepackage{tikz}

\begin{document}
	\begin{tikzpicture}[level/.style={sibling distance=60mm/#1}]
		\node[circle,draw] (root) {\texttt{.OR.}}
			child {node[circle,draw] (a) {\texttt{>=}}
				child {node[circle,draw] (b) {\texttt{/}}
					child {node[circle,draw] (c) {\texttt{/}}
						child {node[] (d) {$i$}}
						child {node[] (e) {$j$}}}
					child {node[] (f) {$x$}}}
				child {node[] (g) {$y$}}}
			child {node[circle,draw] (h) {\texttt{.AND.}}
				child {node[circle,draw] (i) {\texttt{<}}
					child {node[circle,draw] (j) {\texttt{-}}
						child {node[circle,draw] (k) {\texttt{/}}
							child {node[] (l) {$y$}}
							child {node[] (m) {$z$}}}}
					child {node[circle,draw] (q) {\texttt{-}}
						child {node[circle,draw] (p) {\texttt{**}}
							child {node[] (n) {$x$}}
							child {node[circle,draw] (o) {\texttt{**}}
								child {node[] (w) {3}}
								child {node[] (x) {2}}}}}}
				child {node[circle,draw] (r) {\texttt{<=}}
					child {node[] (s) {$char$}}
					child {node[circle,draw] (t) {\texttt{//}}
						child {node[] (u) {'p'}}
						child {node[] (v) {'eter'}}}}};
	\end{tikzpicture}
\end{document}