anchor.diff:          count 
       } @>
   
  -let countThirties = <@ (%countRange) 30 40 @>
  -
  -let ex2correctA = query.Run <@ (%countRange) 30 40 @>   // Counts the number of people in their thirties. 
  -
  -let ex2correctB = query.Run countThirties               // Counts the number of people in their thirties.
  +
  +let countCorrectA = query.Run <@ (%countRange) 30 40 @>   // Counts the number of people in their thirties. 
  +
  +let countCorrectB' = <@ (%countRange) 30 40 @>
  +let countCorrectB = query.Run countCorrectB'              // Counts the number of people in their thirties.
   
   (** 
   
  
positive.code:   } @>
  
  (**
  This way of defining a query exemplifies the logical meaning of the query, and makes it much easier to understand its purpose
  from the code. 
  
  The role of the FSharpComposableQuery library in the evaluation of this query is to normalize it to such a form which can then
  be evaluated as efficiently as the flat query above. In fact, all composite queries which have an equivalent flat form 
  get reduced to it as part of the normalisation procedure.  
  
  
  Higher-order parameters 
  
negative.code: 
  (** 
  
  If, however, a query returns a single value, we cannot use this method - the "yield!" method works only on queries 
  which return rows (collections of base type). We could return the single value using the "yield" keyword, but then the 
  resulting variable will be a collection of exactly one item - instead of just that item.  
  
  In such cases you should pass the query expression to the `query.Run` method instead, which will evaluate it as a value:
  *) 
  
  // Counts the number of people in the given age range. 
  