Lempel-Ziv Complexity

LZ76 algorithm — measuring complexity of binary sequences, compression and entropy
LZ76: parse S into maximal substrings not seen before → C(n) subwords
Normalized: C(n)/[n/log₂(n)] → 1 for random, → 0 for periodic  |  C_LZ ≈ H (entropy rate)
EEG: high LZ during wakefulness, low during anesthesia / slow-wave sleep
LZ words C(n)
Normalized LZ
Entropy H
Compress ratio