High Quality Content by WIKIPEDIA articles! In category theory, a branch of mathematics, a pullback (also called a fibered product or Cartesian square) is the limit of a diagram consisting of two morphisms f : X ? Z and g : Y ? Z with a common codomain; it is the limit of the cospan X rightarrow Z leftarrow Y The pullback is often written P = X times_Z Y , In ожжяж mathematics, category theory deals in an abstract way with mathematical structures and relationships between them: it abstracts from sets and functions to objects linked in diagrams by morphisms or arrows.  В системе2010 г Мягкая обложка, 68 стр ISBN 613034371X.