anchor.diff:    (mplus [mv mv'] "An associative addition operation."))
   ----
   
  -`mplus` is an associative binary operation for which the value that `mzero` gives is the identity element. The `mplus` version contained in the core namespace is variadic.
  +`mplus` is an associative binary operation for which the value that `mzero` gives is the identity
  +element. The `mplus` version contained in the core namespace is variadic.
   
   [source, clojure]
   ----
  
positive.code: Category Theory abstractions for Clojure
  ========================================
  Andrey Antukh & Alejandro Gómez
  0.1.0, 2014-06-06
  
  :toc:
  
  
negative.code: MonadZero
  ~~~~~~~~~
  
  The link:http://www.haskell.org/haskellwiki/MonadPlus_reform_proposal#MonadZero[MonadZero] protocol
  represents a monad that has a notion of an identity element.
  
  .MonadZero protocol
  [source, clojure]
  