Excluding is an act: something excludes everything it is not.
A thing is determined by its inequivalence to anything that is not itself. Given this determination, Excluding is forced alongside Including: the thing must set aside what it is not, just as it must gather what it is. These two acts are co-derived — both forced by the same inequivalence.
Excluding is not a secondary act appended to Including. The original forcing — determination by inequivalence — requires both simultaneously. You cannot specify what something is without specifying what it is not: the two specifications are one act of determination seen from two sides.
Where Including produces Inclusion (the condition of what something is), Excluding produces Exclusion (the condition of what something is not).