3 ms·

I agree for A), by why D) ?

• chias 2y ago
  I suspect a misreading of D) as "The liar has at least one non-green hat" which, in fairness, feels weird that wasn't included in the list.
  • autokad 2y ago
    I did that myself, not sure whats wrong with my eyes >.<
• jblezo 2y ago
  Also, I'm not sure that those two affirmations are equivalent: ~∀x (~IsAHatOfMine(x) ∨ Green(x)) ∃x ~(~IsAHatOfMine(x) ∨ Green(x))
  • FabHK 2y ago
    That's basically "infinite" DeMorgan: https://en.wikipedia.org/wiki/De_Morgan's_laws#Extension_to_predicate_and_modal_logic https://en.wikipedia.org/wiki/De_Morgan's_laws#Extension_to_...