Reverses the state ("True" or "False") of a macro variable. If the variable value is 0 or a zero length (null) string, or if it is undefined, its state is considered to be False. For all other values, its state is considered to be True.
The toggle command sets to 0 ("toggles to False") a variable whose state is True. And it sets to 1 ("toggles to True") a variable whose state is False.
# toggle history
toggle &historyWanted Auto History