Difference between revisions of "Functor"

From Conservapedia
Jump to: navigation, search
m
Line 1: Line 1:
In [[category theory]], a '''functor''' is a type of function between categories. Functors can be thought of as [[morphism]]s in the category of categories.
+
In [[category theory]], a '''functor''' is a [[morphism]] between categories.
  
 
Functors were first proposed in [[algebraic topology]], where algebraic objects such as the [[fundamental group]] are associated to [[topological space]]s, and algebraic [[homomorphism]]s are associated to continuous functions.  Recently, functors are used to relate various categories.
 
Functors were first proposed in [[algebraic topology]], where algebraic objects such as the [[fundamental group]] are associated to [[topological space]]s, and algebraic [[homomorphism]]s are associated to continuous functions.  Recently, functors are used to relate various categories.

Revision as of 21:45, March 14, 2007

In category theory, a functor is a morphism between categories.

Functors were first proposed in algebraic topology, where algebraic objects such as the fundamental group are associated to topological spaces, and algebraic homomorphisms are associated to continuous functions. Recently, functors are used to relate various categories.