+The following syntax and output shows how @code{PCOMPUTE} can compute
+a total over subtotals, summing the ``Frequent Drivers'' and
+``Infrequent Drivers'' subtotals to form an ``All Drivers''
+postcompute. It also shows how to calculate and display a percentage,
+in this case the percentage of valid responses that report never
+driving. It uses @code{PPROPERTIES} (@pxref{CTABLES PPROPERTIES}) to
+display the latter in @code{PCT} format.
+
+@example
+CTABLES
+ /PCOMPUTE &all_drivers=EXPR([1 THRU 2] + [3 THRU 4])
+ /PPROPERTIES &all_drivers LABEL='All Drivers'
+ /PCOMPUTE &pct_never=EXPR([5] / ([1 THRU 2] + [3 THRU 4] + [5]) * 100)
+ /PPROPERTIES &pct_never LABEL='% Not Drivers' FORMAT=COUNT PCT40.1
+ /TABLE=qn1 BY qns3a
+ /CATEGORIES VARIABLES=qn1 [1 THRU 2, SUBTOTAL='Frequent Drivers',
+ 3 THRU 4, SUBTOTAL='Infrequent Drivers',
+ &all_drivers, 5, &pct_never,
+ MISSING, SUBTOTAL='Not Drivers or Missing'].
+@end example
+@psppoutput{ctables35}