Definition
Plain language
The slow, deliberative half of an HRM-style recurrent architecture.
As stated in the literature
In HRM and HRM-Text, the high-level module that updates infrequently and carries longer-horizon state, paired with a fast L module via cyclic recurrence.
Also called: L module, H and L modules
Why it matters: Separating timescales lets a small model keep both reactive detail and long-range structure without paying for full computation at every step.
For example, while the fast L module updates with every token, the H module might only update once per sentence and carry the high-level plan.
Heard on the show
“You wanted to take us into the H and L modules.”Episode 074 — How a Fifteen-Hundred-Dollar Training Run Matched Llama and Gemma on Reasoning