anchor.diff:  
   Note that variable `b` appears in the <ProjectionItem> `b + foo_1 * 2 AS foo` in the RETURN clause.
   However, variable `b` has already by removed from the driving table by the previous projections.
  -In other words, the proposed rewrite produce invalid query text for <<Q6>>.
  +In other words, the proposed rewrite produce invalid query text for <<Q5>>.
   ====
   
   To prevent such invalid rewrites, this CIP imposes a syntax restriction on RETURN and WITH clauses.
  
positive.code: 
  The RETURN clause
  
  .[[Q7]]Q7
  [source, cypher]
  ----
  RETURN a AS a, (b - b) + SUM(c) AS foo
  
negative.code: ====
  A less artificial example is calculating the total gross of an order as the discounted sum of the net values –– product price multiplied by amount –– of the order's line items in query such as:
  
  [source, cypher]
  ----
  MATCH
  