anchor.diff:    (range 5 2 13)
     (range 7 3 -3))
   
  +(document-function rangep
  +  "Checks whether a supplied object is a range."
  +  (rangep 42)
  +  (rangep (range 1 2 3)))
  +
   (document-function size-one-range-p
     "Checks whether the supplied range has a size of one."
     (size-one-range-p (range 5))
  
positive.code: 
   (progn (schedule array-1 array-2)
          (run-expensive-task)
          (compute array-1 array-2)).
  ")
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  
negative.code:   (subdivide (list (~ 1 2 ~ 1 2) (~ 1 ~ 1)))
    (subdivide (list (~ 1 10) (~ 2 20))))
  
  (document-function subshapep
    "Checks for two shapes whether the former is fully contained in the
  latter."
    (subshapep (~) (~))
    (subshapep (~ 0 9) (~ 0 9))
    (subshapep (~ 0 3) (~ 1 9))
    (subshapep (~ 0 3 ~ 0 3) (~ 0 9 ~ 0 9)))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  ;;; Transformations
  