engineering recuitment GATE CSE 2023-24 Test Series Engineering Mathematics Mathematical Logic First Order Logic
Not all days are Sunday.
where D(x) is a day and S(x) is a Sunday.1
∀ x ~(D(x) → S(x))
2
∀ x (D(x) → ~S(x))
3
∃x (D(x) ∧ ~ S(x))
4
∃x (~D(x) ∧ S(x))