Tautologic used in a sentence

Tautologic in a sentence as an adjective

So it's interstate because it doesn't participate in interstate commerce?Do tautologic conclusions make legitimate precedents?

The impossibility to proof the first statement, that of all statements the negation is implied, is surely tautologic, assuming it would hold true for most of all statements, just not a class the opening one is part of.

You're studying the tautologic that you're studyingSickeningly, you're studying illogicYou're a circular logician because you're studying circular logic.