The input is a set T and a set U, where U is a subset of TxTxT.  In other words, U is set of triples, where each triple's elements are from the set T.  The goal is to find a set W that is a subset of U such that W is the same size as T and no 2 elements of W agree in any coordinate.

I've seen a different version of this, and I'm not sure what to do with it.