How to reduce predicate logic into propositional logic? I read that predicate logic reduces into propositional logic. However, I couldn't find anything online that explains the process. Do you know where I could find an explanation? Thank you.

Full predicate logic (with polyadic predicates) cannot be reduced to propositional logic, but **monadic** predicate logic _can_. You can see a sketch of this reduction, e.g., here.