anchor.diff:  WITH AGGR(_L_)
   ----
   
  +Let's call this the _simple rewrite semantics_ for the WITH and RETURN clause.
  +
   .Simple rewrite semantics
   ====
  -With this semantics, the RETURN clause in <<Q3>>
  +With the simple rewrite semantics, the RETURN clause in <<Q3>>
   
   [source, cypher]
   ----
   RETURN b-a AS x, SUM(b*c) AS sumBC`)
   ----
   
  -is defined as effectively equivalent to
  +is effectively equivalent to
   
   [source, cypher]
   ----
  
positive.code: ==== Syntax restriction
  
  The rewrite does not cover all syntactically possible queries.
  
  .Aggregation *not* covered by the rewrite
  ====
  
  By the proposed semantics, the RETURN clause
  
  .[[Q6]]Q6
  [source, cypher]
  
negative.code: 
  The WITH and the RETURN clauses also allow ordering and truncating the driving table, but let's ignore these aspects in this CIP.
  
  === Beyond baseline semantics -- simple rewrite semantics[[simpleRewrite]]
  
  Cypher's WITH and the RETURN are syntactically more flexible when the two baseline semantics.
  In particular, they allow mixing aggregation and projection rather freely.
  