Описать рекурсивную функцию

function TForm1.C(m, n: integer): integer;
var
   i, j, k: integer;
begin
     i := n;
     j := m;
 
     if ((i = n) and (j = 0)) or ((i = n) and (j = n)) then
       C := 1
     else
       C := C(j ,i - 1) + C(j - 1, i - 1);
end;

program Project2;
 
{$APPTYPE CONSOLE}
 
uses
  SysUtils;
 
begin
 
 
Function C(m,n:integer) :integer;
begin
if (m < 0) = (m < n)  then C:= C(n,0) = C(n,n)
else C:= C(m,n) = C(m,n-1) + C(m-1,n-1);
end;
 
begin
Writeln(C(5,7));
 
end.

unit Unit1;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;
 
type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
    function C(m,n: integer): integer;
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.dfm}
 
procedure TForm1.Button1Click(Sender: TObject);
var
   r: integer;
begin
     r := C(10, 20);
     Caption := IntToStr(r);
end;
 
function TForm1.C(m, n: integer): integer;
var
   i, j, k: integer;
begin
     i := n;
     j := m;
 
     if ((i = n) and (j = 0)) or ((i = n) and (j = n)) then
       C := 1
     else
       C := C(j ,i - 1) + C(j - 1, i - 1);
end;
 
end.