anchor.diff:  ----
   (require '[cats.monad.maybe :as maybe])
   
  -;; `just` function is one of two constructors of Maybe
  -
   (maybe/just 2)
   ;; => #<Just [2]>
   ----
   
  +The `just` function is a constructor of Just type that is part of Maybe monad.
  +
   Let's see one example using *fmap* over *just* instance:
   
   .Example using fmap over *just* instance.
   [source, clojure]
   ----
  -(require '[cats.core :as m]
  -         '[cats.monad.maybe :refer [just]])
  -
  -(m/fmap inc (just 1))
  +(require '[cats.core :as m])
  +
  +(m/fmap inc (maybe/just 1))
   ;; => #<Just [2]>
  -----
  -
  -We mentioned above that *fmap* extracts the value from the functor context. You will also want to
  -extract values wrapped by *just* and you can do that with *from-maybe*.
  -
  -.Example using *from-maybe* to extract values wrapped by *just*.
  -[source, clojure]
  -----
  -(require '[cats.monad.maybe :refer [just from-maybe]])
  -
  -(from-maybe (just 1))
  -;; => 1
  -(from-maybe (nothing))
  -;; => nil
  -(from-maybe (nothing) 42)
  -;; => 42
   ----
   
   The *Maybe* type also has another constructor: `nothing`. It represents the absence of a value.
  
positive.code: 
  We will use the _Maybe_ for the example snippets, because it has support for all
  the abstractions and it is very easy to understand. You can read more about it in the next
  section of the documentation.
  
  
  === Functor
  
negative.code: 
  Category Theory abstractions for Clojure.
  
  
  === Why another library?
  
  Because the cats library:
  