Natural Transformation: Mathematics, Category Theory, Morphism

Morphism: Mathematics, Abstraction (mathematics), Map Mathematical structure, Category theory, Concrete category, Set...

Groupoid: Groupoid, Mathematics, Category theory, Homotopy, Group (mathematics), Partial function, Morphism, Isomorphism, Unary operation

Embedding: Mathematics, Mathematical structure, Group (mathematics), Subgroup, Injective function, Category theory, Morphism,...

Dual (category theory): Category Theory, Mathematics, Opposite