Forgetful functor
= Forgetful functor
{wiki=Forgetful_functor}
In category theory, a **forgetful functor** is a type of functor that "forgets" some structure of the objects it maps from one category to another. More specifically, it typically maps objects from a more structured category (e.g., a category with additional algebraic or topological structure) to a less structured category (like the category of sets). \#\#\# Examples 1.