Corrigendum: Emergence of order in random languages (2019 J. Phys. A: Math. Theor. 52 504001)

De Giuli (2019 J. Phys. A: Math. Theor. 52 504001) proposed a diagrammatic formulation of the random language model (RLM); explained why the model is dominated by saddle-points; and sought the solution to the disorder-averaged model by comparison to a simpler, solvable model. We discuss a hidden assumption of the latter analysis in De Giuli (2019 J. Phys. A: Math. Theor. 52 504001) that was neither explained nor motivated: the analytical solution to the Gaussian model, and its extension to the RLM, are predicated on a ‘downwards’ approximation that neglects information flow from the leaves to the root of derivation trees.