 In conclusion to this section, it is important to emphasize that there are no questions of consistency with respect to the above reduction process, because it can be viewed—or described in contemporary terms—as a well-defined algorithm. It is a completely different issue that if we consider the language of FOL expanded with combinators, then the resulting system is inconsistent, because CL is powerful enough to define the fixed point of any function. The effect of having fixed points for all functions—including truth functions—may be thought to amount to adding certain biconditionals (which may or may not be valid) as axioms. (For instance, Russell’s paradox emerges from the fixed point of the negation connective.) Notably, both FOL and (pure) CL are consistent.