An elemantary Forth problem

From	"WJ" <w_a_x_man@yahoo.com>
Newsgroups	comp.lang.forth
Subject	An elemantary Forth problem
Date	2013-09-18 17:51 +0000
Organization	A noiseless patient Spider
Message-ID	<l1cp7o$uss$1@dont-email.me> (permalink)

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Return two lists, the first containing elements that occur only once
in the input list, and the second containing elements that occur more
than once in the input list.

OCaml:

open List;;
let list = ["a";"b";"c";"d";"e";"f";"g";  "b";"b";"d";"f"] in
  let rec loop once twice = function
      []    -> (once,twice)
    | x::xs ->
        if (mem x once) || (mem x twice) then
          loop once twice xs
        else if mem x xs then
          loop once (x::twice) xs
        else
          loop (x::once) twice xs
    in loop [] [] list ;; 

 
(["g"; "e"; "c"; "a"], ["f"; "d"; "b"])


This should be trivial in Forth.

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An elemantary Forth problem "WJ" <w_a_x_man@yahoo.com> - 2013-09-18 17:51 +0000
  Re: An elemantary [sic] Forth problem "Alex McDonald" <blog@rivadpm.com> - 2013-09-18 21:32 +0100
  Re: An elemantary Forth problem mhx@iae.nl - 2013-09-18 14:08 -0700
  Re: An elemantary Forth problem mhx@iae.nl - 2013-09-18 14:58 -0700
  Re: An elemantary Forth problem albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-09-18 22:56 +0000
    Re: An elemantary Forth problem m.a.m.hendrix@tue.nl - 2013-09-18 23:58 -0700
  Re: An elemantary Forth problem VoidVolker <voidvolker@gmail.com> - 2013-09-19 02:25 -0700

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