Возведение квадратной матрицы в куб

unit Unit1;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Grids;
 
type
  TForm1 = class(TForm)
    SG1: TStringGrid;
    SG2: TStringGrid;
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
const n=4;
type matr=array[1..n,1..n] of integer;
var
  Form1: TForm1;
  b:matr;
implementation
 
{$R *.dfm}
procedure UmnMatr(m1:matr;var m2:matr);
var k,i,j:byte;
begin
for k:=1 to n do
for j:=1 to n do
  begin
    m2[k,j]:=0;
    for i:=1 to n do
    m2[k,j]:=m2[k,j]+m1[k,i]*b[i,j];
  end;
end;
 
procedure TForm1.Button1Click(Sender: TObject);
var i,j:byte;
begin
randomize;
SG1.ColCount:=n;
SG1.RowCount:=n;
SG2.ColCount:=n;
SG2.RowCount:=n;
for i:=1 to n do
for j:=1 to n do
b[i,j]:=random(21)-10;
for i:=1 to n do
for j:=1 to n do
SG1.Cells[j-1,i-1]:=Inttostr(b[i,j]);
end;
 
procedure TForm1.Button2Click(Sender: TObject);
var a,c:matr;
    i,j:byte;
begin
UmnMatr(b,a);//умножаем b*b=a
UmnMatr(a,c);//умножаем a*b=c
for i:=1 to n do
for j:=1 to n do
SG2.Cells[j-1,i-1]:=Inttostr(c[i,j]);
end;
 
end.