Facet filters: How to generate "everything but this combo"

I’m working with a pair of facets and need to create two subsets of data: One that matches a particular pair of values and one that matches everything but that specific pair of values.

So, for example, if this was guitars and one subset was
(is_electric:"true") AND (is_six_string:"true")
and the other subset needed to cover every other possible combination of values except this specific pair, how might that be handled?