anchor.diff:  }
   ----
   
  -== Arrays
  +== Array (data structure)
   
   The first data structure we'll explore is the *array*.
   
  
positive.code: ----
  
  
  == Tuples
  
  The *tuple* is the next data structure we'll explore.
  
  
negative.code: }
  ----
  
  == Let (setting variables)
  
  The `let` function sets *variables* and runs a Streaming Expression that references the variables. The `let` funtion can be used to
  write small statistical programs.
  