Huffman coding

In your fractal data, you can compress the huge chain. It depends on frequency of occurrence, so if you use more, you can shorten the code.

You have BACE. This is 001000010100 which is 4*3=12 bits. You put A is 0 and B is 1. BACE is 10010100. This is 8 bits which is about 67% compression. MP3 and JPEG are well known.

This is the information content h (in bits) of each symbol ai with non-null probability, which are binary.

The entropy H (in bits) is the weighted sum, across all symbols ai with non-zero probability wi, of the information content of each symbol.