anchor.diff:  
   === Scan
   
  -Allows combine all results of an observable sequence using a combining function
  -also called (reducing function). Returns a stream of each intermediate result
  -instead of:
  +Like `reduce` (see above), but returns a stream of each intermediate result
  +instead (similar to `reductions` in Clojure):
   
   [source, clojure]
   ----
  
positive.code: 
  === From a collection
  
  The most basic way to create a stream is just take a collection
  and convert it in an observable sequence:
  
  [source, clojure]
  ----
  
negative.code: ;; ==> on-end
  ----
  
  Or skip until another observable yields a value with `skip-until` (no example at
  this moment).
  
  
  === Take
  
  You can also limit the observable sequence to an specified number of elements:
  
  [source, clojure]
  ----
  