Pro Set trading cards product, which could make and issue cards very quickly. For its first football card set in 1989, Pro Set released its cards in three series. The 1989 rookies were found primarily in the second series. Key rookies in the set included Troy Aikman, Barry Sanders, Derrick Thomas, Jeff Lageman and Deion Sanders. The 100 card Series II set was sold in packs, but the packs averaged 11 Series I cards and 4 Series II cards per pack. These cards not only featured first round picks but featured later round picks. These cards were labelled as Pro Set Prospects. At its
Partition of a set into the connected components of the subgraph formed by the given set of edges. In this way, the lattice of partitions corresponds to the lattice of flats of the graphic matroid of the complete graph. Another example illustrates the refining of partitions from the perspective of equivalence relations. If "D" is the set of cards in a standard 52-card deck, the "same-color-as" relation on "D" – which can be denoted ~ – has two equivalence classes: the sets {red cards} and {black cards}. The 2-part partition corresponding to ~ has a refinement that yields the "same-suit-as" relation ~, which has