The UNION Operation
- Let’s assume that we have an equivalence relation R, and a set of induced equivalence classes {E1, E2 , E3 , ... , Ek}
- UNION( Ei, Ej ) changes the partition so that Ei and Ej have been merged into one subset.
- For example, after UNION(E2, E3) we have {E1, E2 U E3 , ... , Ek }
- Note: Each Ei can be represented by its represent. element. So it’s OK to write UNION(a, d)