Definition
A quiver Γ consists of:
- The set V of vertices of Γ
- The set E of edges of Γ
- Two functions: s:E→V giving the start or source of the edge, and another function, t:E→V giving the target of the edge.
This definition is identical to that of a multidigraph.
A morphism of quivers is defined as follows. If and are two quivers, then a morphism of quivers consist of two functions and such that following diagrams commute:
and
Read more about this topic: Quiver (mathematics)
Famous quotes containing the word definition:
“Mothers often are too easily intimidated by their childrens negative reactions...When the child cries or is unhappy, the mother reads this as meaning that she is a failure. This is why it is so important for a mother to know...that the process of growing up involves by definition things that her child is not going to like. Her job is not to create a bed of roses, but to help him learn how to pick his way through the thorns.”
—Elaine Heffner (20th century)
“Perhaps the best definition of progress would be the continuing efforts of men and women to narrow the gap between the convenience of the powers that be and the unwritten charter.”
—Nadine Gordimer (b. 1923)
“The definition of good prose is proper words in their proper places; of good verse, the most proper words in their proper places. The propriety is in either case relative. The words in prose ought to express the intended meaning, and no more; if they attract attention to themselves, it is, in general, a fault.”
—Samuel Taylor Coleridge (17721834)