 Strict initial object

An initial object $0$ is strict when every morphism into $0$ is invertible. Adjoining a new strict initial object to a category means adding one map from it to every object and no map to it from any old object. Its only endomorphism is the identity.

In category theory, a **strict initial object** is an object \( I \) in a category \( \mathcal{C} \) such that for every object \( A \) in \( \mathcal{C} \), there exists a unique morphism (also called an arrow) from \( I \) to \( A \).