Statements are often denoted by letters such as p, q, and r.

We often used p, q, and r to stand propositional statement or logical statement. We can see this in the truth tables where p can represent the true statement and q represents the false statement while r for the r represents the result of the logical condition. In using these letters, we can merely remove the parenthesis in between the letters since by writing the letters side-by-side would also mean multiplication such as pq = p(q).