Operations On Families
Index sets are often used in sums and other similar operations. For example, if (ai)i∈I is a family of numbers, the sum of all those numbers is denoted by
When (Ai)i∈I is a family of sets, the union of all those sets is denoted by
Likewise for intersections and cartesian products.
Read more about this topic: Indexed Family
Famous quotes containing the words operations and/or families:
“You can’t have operations without screams. Pain and the knife—they’re inseparable.”
—Jean Scott Rogers. Robert Day. Mr. Blount (Frank Pettingell)
“Many older wealthy families have learned to instill a sense of public service in their offspring. But newly affluent middle-class parents have not acquired this skill. We are using our children as symbols of leisure-class standing without building in safeguards against an overweening sense of entitlement—a sense of entitlement that may incline some young people more toward the good life than toward the hard work that, for most of us, makes the good life possible.”
—David Elkind (20th century)