PlanetPhysics/Commutative Triangle Diagram

A commutative triangle diagram, $$T_{CD}$$, which is represented geometrically as: $$\begin{xy} \xymatrix{ {A}\ar[rr]^{f}\ar[dr]_{h}&&{B}\ar[dl]^{g}\\ &{C}& } }\end{xy}$$ is also defined algebraically by the equality $$h=g\circ f$$
 * !C\xybox{