SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    Function isNull (children 1)
     ExpressionList (children 1)
      Identifier f
    Function isNotNull (children 1)
     ExpressionList (children 1)
      Identifier f
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier decimal
   Function equals (children 1)
    ExpressionList (children 2)
     Identifier a
     Function toDecimal32 (children 1)
      ExpressionList (children 2)
       Literal Float64_5.5
       Literal UInt64_1