3. (5+5 points) (a) Let ICS(P), 41, ..., An, O E S(P). Show that if T +41, 142, ...,1+ Sn and 41, ..., Ant 0, then T F 8. Apply this to show that if T, 60 and r4, then T F 0. (b) Prove the formal theorem (8V1) = 4. 3. (5+5 points) (a) Let ICS(P), 41, ..., An, O E S(P). Show that if T +41, 142, ...,1+ Sn and 41, ..., Ant 0, then T F 8. Apply this to show that if T, 60 and r4, then T F 0. (b) Prove the formal theorem (8V1) = 4