# Contravariant Functor A contravariant functor is a type `E<a>` that has an operator `contramap` with the following signature: ``` contramap : E<b> -> f : (a -> b) -> E<a> ``` A .NET `Predicate<T>` is a contravariant functor. For a regular functors see [[Covariant Functor|Covariant Functor]].