Binary relation in a cartesian product

How many binary relation can be formed from the cartesian product below:
A = { 1 , 2 } & B = {a }
i know there are two ordered pairs in this cartesian products A * B.
i also know that there are 4 binary realtions. could someone please write
those four relations for me, i am really confused here.


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{(1, a)}, {(2, a)}, {(a, 1)}, and {(a, 2)}.
{(1, a)}, {(2, a)}, {(a, 1)}, and {(a, 2)}.
I'd imagine, they're actually something more like these: {}, {(1, a)}, {(2, a)}, and {(1, a), (2, a)}...
thanx. i really apprecite u for this

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