Figure 4From: RNACompress: Grammar-based compression and informational complexity measurement of RNA secondary structureHuffman coding of production rules of G 1 . This binary tree is generated from left to right taking the two least probable symbols and putting them together to form another equivalent symbol having a probability that equals the sum of the two symbols. The process is iterated until we have only one symbol. Finally, the tree is read backwards, from right to left, to assign different bits to different branches.Back to article page