is a variable defined in `
Its value is
If non-nil, use a separate face to indicate selected sub-formulas.
If option `calc-show-selections' is non-nil, then selected sub-formulas are
shown by displaying the rest of the formula in `calc-nonselected-face'.
If option `calc-show-selections' is nil, then selected sub-formulas are shown
by displaying the sub-formula in `calc-selected-face'.
You can customize this variable.
This variable was introduced, or its default value was changed, in
version 24.1 of Emacs.