Exercise: Let R be a relation on people such that (a,b) is" a is a parent of b Let S be a relation on people such that (a,b) is "a is a sibling of b" What is SOR, ROS, ROR? SoR composes R with S (a,c) is in SoR if there exists (a,b) in R and a(b, c) in S "a is parent of b" and "b is sibling of c " SoR should be in R! RoS composes S with R "a is sibling of b" and "b is a parent of c" therefore (a,c) is "a is an aunt/uncle of c " I DIDNT UNDERSTAND THAT WHERE C CAME FROM PLEASE EXPLAIN DETAILED