3. (20 points) Propositional Operations and Equivalences
All propositional logic statements can be expressed by using ¬, ∧, ∨, →, ↔, T (true) and F (false). Not all
of these 7 symbols are vital to express all statements. For instance instead of F we can use ¬T, or instead
of P ∧ Q we can use ¬(¬P ∨ ¬Q). Actually P ↔ Q is usually interpreted as (P → Q) ∧ (Q → P) most of
the time. So if we have → and ∧ we dont need ↔ at all. That is to say a shorter list of symbols might be
enough to express all possible statements.
• Show that → and F is enough to express any propositional logic statement. (Express ¬P, P ∧ Q, P ∨ Q
and T, by using only P, Q, → and F.)