type Person = FPerson | MPerson;; 
type FPerson = <person gender = "F" >[ Name Children ];; 
type MPerson = <person gender="M">[ Name Children ];; 
type Children = <children>[Person*];; 
type Name = <name>[ PCDATA ];;

type Man = <man name=String>[ Sons Daughters ];;
type Woman = <woman name=String>[ Sons Daughters ];;
type Sons = <sons>[ Man* ];;
type Daughters = <daughters>[ Woman* ];;

let fun split (Person -> Man | Woman)
 <person gender=g>[ <name>n <children>c ] ->
   let tag = match g with "F" -> `woman | "M" -> `man in
   match (map c with x -> split x) with [ (s::Man|d::Woman)* ] ->
   <(tag) name=n>[ <sons>s  <daughters>d ] 
;; 

let x = 
  match argv [] with
   | [src] -> 
       (match (load_xml src :? <doc>[Person*]) with
         <doc>l -> dump_xml_utf8 <doc>(map l with x -> split x))
   | _ -> raise "Invalid command line";;