Suppose F(x) is the formula: \text { " } x \in \mathbb{N} \text { and } x \text { is a multiple of } 4 . " Let E(x) be the formula: \text { " } x \text { is even." } Then \[(\forall x)...Suppose F(x) is the formula: \text { " } x \in \mathbb{N} \text { and } x \text { is a multiple of } 4 . " Let E(x) be the formula: \text { " } x \text { is even." } Then (\forall x)[F(x) \Rightarrow E(x)] . It does not suffice to observe that 4,8 and 12 are all even.