NSUInteger local fn Damm( string as CFStringRef )
  mda(0,0) = {{0,3,1,7,5,9,8,6,4,2},
  {7,0,9,2,1,5,4,8,6,3},{4,2,0,6,8,7,1,3,5,9},
  {1,7,5,0,9,8,3,4,2,6},{6,1,2,3,0,4,5,9,7,8},
  {3,6,7,4,2,0,9,5,8,1},{5,8,6,9,7,2,0,1,3,4},
  {8,9,4,5,3,6,2,0,1,7},{9,4,3,8,6,1,7,2,0,5},
  {2,5,8,1,4,3,6,7,9,0}}

  NSUInteger i, colI, oldRowI = 0, newRowI
  for i = 0 to len(string) - 1
    colI = intval(string[i])
    newRowI = mda(oldRowI,colI)
    oldRowI = newRowI
  next
end fn = newRowI

void local fn DoIt
  CFArrayRef dta = @[@"5724",@"5727",@"112946",@"112949"]
  for CFStringRef string in dta
    print string;
    if ( fn Damm( string ) == 0 )
      print @" is valid"
    else
      print @" is invalid"
    end if
  next
end fn

fn DoIt

HandleEvents