Machine-translated by Google. Questions are authored in English.
Top

Discussion

What is wrong with writing some student is diligent using implication?

  • A.Any non-student satisfies it vacuously
  • B.It claims every student is diligent
  • C.It claims no student is diligent
  • D.It cannot be written with the existential quantifier

Answer: A

Writing there exists x such that x is a student implies x is diligent is made true by any object that is not a student, since a false antecedent makes the implication true, so the sentence says almost nothing. The formula is satisfied in a domain containing a single stone. Recognising vacuous satisfaction as the mechanism of the error connects it to the same phenomenon in universal restrictions in description logics.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.