The author primarily talks about the compression–prediction equivalence and also provides some working code linked in Github
https://github.com/nathan-barry/gziptEvery prediction model is inherently a compressor, and all compression algorithms are prediction models.
Reference:
Language Modeling Is Compression — Delétang et al., DeepMind, 2023. The prediction-compression equivalence, with the Chinchilla-beats-PNG result.