Prove that the set {∨,∧, ⇒,¬} is universal. (Hint: To do so, you need to show that, for each column 1 through 16 of Figure 4.31, you can build a Boolean expression ϕi over the variables p and q that...

Prove that the set {∨,∧, ⇒,¬} is universal. (Hint: To do so, you need to show that, for each column 1 through 16 of Figure 4.31, you can build a Boolean expression ϕi over the variables p and q that uses only the operators {∨, ∧,⇒, ¬}, and such that ϕi is logically equivalent to p i q.)