Spahn couniversal mapping property 1 (Rev #4, changes)

Showing changes from revision #3 to #4: Added | Removed | Changed

Let F:XCF:X\to C be a functor between categories. A CC morphism f:aF(x)f:a\to F(x) is called to satisfy the couniversal mapping property with respect to FF, if f=0C/Ff=0\in C/F is initial in the comma category C/FC/F. or we say that ff is a couniversal arrow from cc to FF or that ff is the initial arrow from cc to FF, if f=0C/Ff=0\in C/F is initial in the comma category c/Fc/F.

This means: for any yXy\in X and any morphism ϕ:aG(y)\phi:a\to G(y) there is a morphism ψ:xy\psi:x\to y such that

a f F(x) ϕ G(ψ) G(y)\array{ a&\stackrel{f}{\mapsto}&F(x) \\ &\searrow^\phi&\downarrow^{G(\psi)} \\ &&G(y) }

commutes.

For cCc\in C the initial object f:cF(x)f:c\to F(x) in c/Fc/F is called couniversal arrow from cc to RR.

Revision on July 15, 2012 at 15:14:25 by Stephan Alexander Spahn?. See the history of this page for a list of all contributions to it.