A projection morphism is one of the canonical morphisms from a product or fiber product to one of its factors. For a fiber product 
, the projections
 |  |
(1)
|
 |  |
(2)
|
 |
(3)
|
satisfy 
and occur in its universal property.
Projection Morphism
See also
Fiber Product, Morphism, Pullback, Universal PropertyExplore with Wolfram|Alpha
References
Mac Lane, S. Categories for the Working Mathematician, 2nd ed. New York: Springer-Verlag, 1998.Cite this as:
Weisstein, Eric W. "Projection Morphism." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/ProjectionMorphism.html