 Compact closed category

A **compact closed category** is a concept from category theory, a branch of mathematics that deals with abstract structures and relationships between them. Compact closed categories provide a framework in which one can model concepts from topology, linear logic, and quantum mechanics, among other fields. Here are some key features and definitions related to compact closed categories: 1. **Categories**: A category consists of objects and morphisms (arrows) between those objects, where morphisms must satisfy certain composition and identity properties.