# What is this notation

• Sep 26th 2011, 07:34 PM
dwsmith
What is this notation
After the f o g and g o f, there is a something and a v.

What is that?
• Sep 26th 2011, 08:31 PM
Drexel28
Re: What is this notation
Quote:

Originally Posted by dwsmith
After the f o g and g o f, there is a something and a v.

What is that?

That is an iota. Usually it indicates an \.
• Sep 26th 2011, 11:38 PM
zoek
Re: What is this notation
Quote:

Originally Posted by dwsmith
After the f o g and g o f, there is a something and a v.

What is that?

$\iota_V:V \to V, \,\,\,\iota_{V}(x) = x, \,\,\forall x \,\in V$.
• Sep 27th 2011, 12:39 AM
Deveno
Re: What is this notation
normally iota is used for an inclusion morphism. if the sub-object is the same as the target of the morphism (just as any set can be a subset of itself), then this becomes the identity map.