anchor.diff:  
   [source, cypher]
   ----
  -RETURN a AS a, (a + SUM(b*c) - MIN(c)) * 2 AS agg
  +RETURN a AS a, (a + SUM(b*c) - MIN(c)) * 2 AS foo
   ----
   
   is effectively equivalent to
  
positive.code: ** Let `_PROJ_(_p_)` be `_ex_ AS _al_` and
  ** Let `_AGGR_(_p_)` be `_agg_(_al_) AS _al_`
  
  With this, `RETURN _p_~1~, _p_~2~, ... _p~N~_` can be defined as effectively equivalent to
  
  [source, cypher, subs="quotes"]
  ----
  
negative.code: RETURN _POST_PROJ_(_p_~1~), _POST_PROJ_(_p_~2~), ..., _POST_PROJ_(_p~N~_)
  ----
  
  Analogously, `WITH _p_~1~, _p_~2~, ..., _p~N~_` is effectively equivalent to
  
  [source, cypher, subs="quotes"]
  ----
  