A covariant functor is a functor 
that preserves the directions of arrows, i.e., every arrow
is mapped to an arrow 
.
Covariant Functor
See also
Contravariant Functor, Forgetful Functor, Functor, Hom, Tensor Product FunctorThis entry contributed by Margherita Barile
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Cite this as:
Weisstein, Eric W., with contributions by Margherita Barile. "Covariant Functor." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/CovariantFunctor.html