SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 3)
    Literal \'{a\' (alias x)
    Function like (children 1)
     ExpressionList (children 2)
      Identifier x
      Identifier x (alias pat)
    Function like (children 1)
     ExpressionList (children 2)
      Function materialize (children 1)
       ExpressionList (children 1)
        Identifier x
      Identifier pat
