local fn Checksum( s as CFStringRef ) as CFStringRef
  CFStringRef v = @"0123456789-BCD-FGH-JKLMN-PQRST-VWXYZ", w = @"131739"
  long i, sum = 0
  for i = 0 to len(s) - 1
    CFRange r = fn StringRangeOfString( v, mid(s,i,1) )
    if ( r.location == NSNotFound ) then return NULL
    sum += r.location * intval(mid(w,i,1))
  next
end fn = concat( s, @((10 - (sum % 10)) % 10) )

void local fn DoIt
  CFArrayRef sedols = @[
  @"710889",
  @"B0YBKJ",
  @"406566",
  @"B0YBLH",
  @"228276",
  @"B0YBKL",
  @"557910",
  @"B0YBKR",
  @"585284",
  @"B0YBKT",
  @"B00030",
  @"ABCDEF"]
  CFStringRef sedol
  for sedol in sedols
    CFStringRef s = fn Checksum( sedol )
    if ( s ) then print s : continue
    print @"Invalid"
  next
end fn

fn DoIt

HandleEvents