It is a virtue of FS that it is thoroughly classical: It is formulated in classical logic; if a sentence is provably true in FS, then the sentence itself is provable in FS; and conversely if a sentence is provable, then it is also provably true. Its drawback is its \(\omega\)-inconsistency. FS may be seen as an axiomatization of rule-of-revision semantics for all finite levels (see the entry on the revision theory of truth).