Thread: What is this notation

After the f o g and g o f, there is a something and a v.

What is that?

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 \.

Originally Posted by dwsmith

After the f o g and g o f, there is a something and a v.

What is that?

.

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.