Establish rules for null quantification that we can use when a quantified variable does not appear in part of a statement. Establish these logical equivalences, where x does not occur as a free variable in A. Assume that the domain is nonempty. a) (∀xP (x)) ∨ A ≡ ∀x(P (x) ∨ A) b) (∃xP (x)) ∨ A ≡ ∃x(P (x) ∨ A)
