Set (card game) Set (card game) Set is a real-time card game designed by Marsha Falco in 1974 and published by Set Enterprises in 1991. The deck consists of 81 cards varying in four features: number (one, two, or three); symbol (diamond, squiggle, oval); shading (solid, striped, or open); and color (red, green, or purple). Each possible combination of features (e.g., a card with three striped green diamonds) appears precisely once in the deck. The game evolved out of a coding system that the designer used in her job as a geneticist. "Set" won American Mensa's "Mensa Select" award in 1991 and placed
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