Citations:discrete category

• 2004, Joachim Kock, Frobenius Algebras and 2-D Topological Quantum Field Theories, Cambridge University Press (Template:ISBN), page 157:

  Thus a discrete category is specified completely by specifying its objects. Conversely, every set S can be considered a discrete category S: just take the objects of S to be the elements of S, and take no arrows other than the identity arrows.

• 2014, David I. Spivak, Category Theory for the Sciences, MIT Press (Template:ISBN), page 284:

  Let $n\in \mathbb{N}$, and let n be the set with n elements, considered as a discrete category. ¹³ In other words, we write n to mean what should really be called Disc(n).

• 2014, Tom Leinster, Basic Category Theory, Cambridge University Press (Template:ISBN), page 27:

  To see how this might work, let us consider a special case. Let $𝒜$ be the discrete category (Example 1.1.8(b)) whose objects are the natural numbers 0, 1, 2, .... A functor F from $𝒜$ to another category $ℬ$ is simply a sequence $(F_0,F_1,F_2,...)$ of objects of $ℬ$.