I'm going to ask a quite vague question, since the borderline between theoretical computer science and math is not always easy to distinguish.QUESTION: Are you aware of any interesting result in CS which is either independent of ZFC (i.e. standard set theory),or that was originally proven in ZFC (+ some other axiom) and only later proven in ZFC alorne?I'm asking because I'm close to finish my PhD thesis, and my main result (the determinacy of a class of games which are used to give game semantics to a probabilistic modal $\mu$-calculus) is at the moment proven in ZFC extended with other Axioms (namely the negation of the Continuum hypothesis $\neg CH $ and, Martin's Axiom $MA$).So the setting is clearly Computer Science (the modal $\mu$-calculus is a temporal logic, and I'm extending it to work with probabilistic systems).I would like to cite in my thesis other examples (if you are aware of any) of this kind.Thank you in advance,byeMatteo 
Results in Theoretical CS independent of ZFC
reference request;lo.logic;set theory