Match on empty list instead of pattern variable in interp-R1

book.tex

@@ -1227,7 +1227,7 @@ environment with the result value bound to the variable, using
 
 (define (interp-R1 p)
   (match p
-    [(Program info e) ((interp-exp '()) e)]
+    [(Program '() e) ((interp-exp '()) e)]
     ))
 \end{lstlisting}
 \caption{Interpreter for the $R_1$ language.}