In the following sentence, the “and/or” seems odd in a case of total negation:
Evidently some people are not able to interpret and/or analyze at that deeper level.
Because the sentence says “are not able to”, total negation would seem to unambiguously require “or”.
In a positive sentence, “and/or” is sometimes used to mean inclusive OR (although perhaps OR alone could suffice), but is there any possibility of ambiguity in total negation?
In other words
Not X and not Y = Not X or Y
Would “not X and/or Y” ever be required? Or does such use merely reflect the increasing proliferation of superfluous “and/or”?