:variable PLACE The location to use instead of the variable MODE to store
the state of the mode. This can be simply a different
named variable, or a generalized variable.
- PLACE can also be of the form \(GET . SET), where GET is
+ PLACE can also be of the form (GET . SET), where GET is
an expression that returns the current state, and SET is
a function that takes one argument, the new state, and
sets it. If you specify a :variable, this function does