SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Identifier a.x (alias x)
   TablesInSelectQuery (children 3)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier a
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier b
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier a.x
        Identifier b.x
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier c
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier a.x
        Identifier c.x
