SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 2)
    Identifier t1.a (alias a)
    Identifier t2.c (alias c)
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier t1
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier t2
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier c
        Identifier a
