Composites of relations
Let R be a relation from A to B and S a relation from B to C. The
composite of R and S, denoted by R?S, is a relation from A to C
For all a?A and c?C, a(R?S)c iff there is b?B s.t. aRb and bRc.
Example: The composite of the relations “… is a son of …” and
“… is a daughter of …” is
Let R be a relation on A. The powers Rn, n=1,2,3,…, are defined
Example: Let R be the relation “… is a parent of …”. Then
“… is a grandparent of …”
“… is a great grandparent of …”