Lesson 7: Laws of the bifunctors

  • The Bifunctor laws
  • Inputs and shrinkage
  • Ranges
  • Identity tests
  • Make them fail
  • Composition laws
  • Coming up

In the previous lesson we looked at an interesting bifunctor, but in this lesson we’re going to come back to the Data.Bifunctor module and its laws. Since the Bifunctor laws are closely related to the Functor laws, this lesson will rely on lesson 4 and will not spend too much time redoing work that we already did there. However, there are some interesting things to look at here.

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