Direct Sum of Rings
Given a finite family of rings R1, ..., Rn, the direct product of the Ri is sometimes called the direct sum.
Note that in the category of commutative rings, the direct sum is not the coproduct. Instead, the coproduct is the tensor product of rings.
Read more about this topic: Direct Sum
Famous quotes containing the words direct, sum and/or rings:
“Pleasure is the rock which most young people split upon; they launch out with crowded sails in quest of it, but without a compass to direct their course, or reason sufficient to steer the vessel; for want of which, pain and shame, instead of pleasure, are the returns of their voyage.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)
“To help, to continually help and share, that is the sum of all knowledge; that is the meaning of art.”
—Eleonora Duse (1859–1924)
“Ah, Christ, I love you rings to the wild sky
And I must think a little of the past:
When I was ten I told a stinking lie
That got a black boy whipped....”
—Allen Tate (1899–1979)