anchor.diff:  
   [source, clojure]
   ----
  -(def stream (s/zip
  -              (s/from-coll [1 2 3])
  -              (s/from-coll [2 3 4])))
  -
  -(s/subscribe stream
  -             #(println "on-value:" %)
  -             #(println "on-error:" %)
  -             #(println "on-end"))
  +(def stream (rx/zip
  +              (rx/from-coll [1 2 3])
  +              (rx/from-coll [2 3 4])))
  +
  +(rx/subscribe stream
  +              #(println "on-value:" %)
  +              #(println "on-error:" %)
  +              #(println "on-end"))
   
   ;; ==> on-value: [1 2]
   ;; ==> on-value: [2 3]
  
positive.code: 
  [source, clojure]
  ----
  (def sub (s/on-end sub #(println "end!")))
  ----
  
  === Consume error termination
  
negative.code: 
  [source, clojure]
  ----
  (def stream (rx/empty))
  ----
  
  This stream not yelds any value and just terminates.
  