AI MCQ #305: The statement comprising the limitations of FOL is/are ____________

Q305. The statement comprising the limitations of FOL is/are ____________

  • a) Expressiveness
  • b) Formalizing Natural Languages
  • c) Many-sorted Logic
  • d) All of the mentioned

✅ Correct Answer: D) All of the mentioned

Explanation: The Löwenheim–Skolem theorem shows that if a first-order theory has any infinite model, then it has infinite models of every cardinality. In particular, no first-order theory with an infinite model can be categorical. Thus there is no first-order theory whose only model has the set of natural numbers as its domain, or whose only model has the set of real numbers as its domain. Many extensions of first-order logic, including infinitely logics and higher-order logics, are more expressive in the sense that they do permit categorical axiomatizations of the natural numbers or real numbers. This expressiveness comes at a meta-logical cost, however: by Lindström’s theorem,