A potentially useful application for the <<*Set*>> commands is to compare or add (or subtract) the values of one or more existing !groupname! values.
<<*AskRepeat*!NumCats!*How many cats?>>
<<*AskRepeat*!NumDogs!*How many dogs?>>
The resulting value of !NumCritters! can be used anywhere in the document. E.g.,
We have <<!numcats!>> cats and <<!numdogs!>> dogs. <<!NumCritters!>> pets may seem like a lot, but it's just right for me.