Quote by Saunders MacLane
““If P is a presheaf on C and x E P(C), the value for an arrow f : D -* C in C is called the restriction of x along f, and is often denoted by I or by a dot:””
““If P is a presheaf on C and x E P(C), the value for an arrow f : D -* C in C is called the restriction of x along f, and is often denoted by I or by a dot:””