2. Which statement is the only one that is always true, and why? (5 points) a. pr(s(n)) = n for all ne N b. s(pr(n)) = n for all ne N 3. Give a recursive definition of the relation FOURMORE on the natural numbers, where FOURMORE = {(x,y) E NXNx= y + 4). (15 points) 4. Give a recursive definition of the greater than relation GT on the natural numbers, where GT = {(x,y) NxNx>y}. (15 points) 5. Draw a Venn diagram (where circles/ovals represent the sets inside the box denoting the universe) showing the relationship between GT and FOURMORE. Explain your reasoning. (5 points) 6. Give a recursive definition of the relation FOURLESS on the natural numbers, where FOURLESS = ({x,y) e NxNx=y-4}. (15 points) 7. Draw a Venn diagram showing the relationship between FOURLESS and LT, as defined in class, LT = {(x, y) E NXNX