A category is thin iff each Homset has at most one morphism.
Remarks
There is an isomorphism between the category of thin categories and the category of posets, so they can be though of as the same category.
A category is thin iff each Homset has at most one morphism.
There is an isomorphism between the category of thin categories and the category of posets, so they can be though of as the same category.