14th of December, 2025 The Chomsky hierarchy is a way to classify text-generating algorithms (formally called languages) by how expressive they are. Since generative pretrained transformers, GPTs, are getting quite a bit of attention these days, one might wonder where in the hierarchy they fall. To give a classic example of one category in the hierarchy, context-free languages are those whose strings are produced by iteratively applying rules that locally expand grammar particles into words. Thi...