What are the De Morgans laws for quantifiers?
¬ (∀x.P(x)) ≡ ∃x.¬P(x)
¬ (∃x.P(x)) ≡ ∀x.¬P(x)
Is this true or false? ∀x∃y. Q(x,y) ≡ ∃x∀y.Q(x,y)
False
Is this true or false? ¬(∀x.P(x)) ≡ ∃x.¬P(x)
False
Is this true or false? ∀x∀y. Q(x,y) ≡ ∀y∀x. Q(x,y)
True
Is this true or false? ∀x.¬P(x) ≡ ∃x.¬P(x)
False