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**CPR** Here is my problem:

Let H= {1,2,3,4}, A = HxH, and define a relation on A by (s,t) R(u,v) if and only if st = uv.

1. Show R is an equivalence relation on A.

2. Compute the partition A/R that corresponds to the equivalent relation.

This is what I have:

R= (1,1), (1,2), (1,3),(1,4), (2,1), (2,2),(2,3),(2,4),(3,1),(3,2),(3,3),(3,4),(4,1), (4,2), (4,3),(4,4).

It is reflexive, symmetric, and transitive. Therefore it is an equivalence relation.

R(1) = {1,2}, R(3) {3,4}

However, I am not sure about the partition A/R. Please help.