Core groupoid

Let $𝖢$ be a category. The core of $𝖼 𝗈 𝗋 𝖾 (𝖢)$ is the groupoid whose objects are the objects of $𝖢$ and whose morphisms are the isomorphisms of $𝖢$ . #m/def/cat Thus it is the “universal” groupoid embedding into $𝖢$ .

#state/tidy | #lang/en | #SemBr