Consider: D: collection of all positive integers . What can you say about the truth value of the following statement? exists x in D, exists y in D, exists z in D,x^ 2 +y^ 2 =z^ 2 True, because x = 3; y = 4 , z = 5 satisfy the above condition . True, because every value of , y , z in the domain satisfies the above condition . False, because no , y, z in the domain can satisfy the above condition . False , because x = 1; y = 1z = 2 make the predicate false