procedure mprod(var m1,m2,m3: matrix);
var
  i,j,k: integer;
  s0,s1,s2: scalar;
begin { mprod }
  for i:=0 to lmax do for k:=0 to lmax do begin
    szero(s0);
    for j:=0 to lmax do begin
      sprod(m1[i,j],m2[j,k],s1);
      ssum(s0,s1,s2);
      s0:=s2;
    end;
    m3[i,k]:=s0;
  end;
end { mprod };