type VersNoeud= ^Noeud;
     Noeud= record
              Desc: array['a'..'z'] of VersNoeud;
              Complet: boolean;
              end; { Noeud }

var Dico: VersNoeud;

function Trouve(LeDico: VersNoeud; LeMot: string)
               : boolean;
begin { Trouve }
  if LeDico=nil then Trouve := false
  else if LeMot = '' then Trouve := LeDico^.Complet
  else Trouve := Trouve(LeDico^.Desc[LeMot[1]],
                        copy(LeMot,2,length(LeMot)-1));
end; { Trouve }

{ version non-recursive }
function Trouve(LeDico: VersNoeud; LeMot: string)
               : boolean;
var i: integer;
    Courant: VersNoeud;
begin { Trouve }
  i:=1;
  Courant := LeDico;
  while (i<=Length(LeMot)) and (Courant<>nil) do begin
    Courant := Courant^.Desc[LeMot[i]];
    i := i+1;
    end; { while }
  if Courant=nil then Trouve := false
  else Trouve := Courant^.Complet;
end; { Trouve }

procedure Imprime(LeDico: VersNoeud);

  procedure Print(N: VersNoeud; S: string);
  var i:char;
      Splus:string;
  begin
    if N^.Complet then writeln(S);
    Splus := Insert(' ',S, length(S)+1);
    for i := 'a' to 'z' do 
      if N^.Desc[i]<>nil then begin
        Splus[length(Splus)] := i;
        Print(N^.Desc[i],Splus);
        end; { if N^.Desc[i]<>nil }
  end; { Print }

begin { Imprime }
  if LeDico<>nil then Print(LeDico, '');
end; { Imprime }