D262 - Repeated learned became affordable when the list shrank, and nobody noticed

decided · 2026-08-25 · a consequence of somebody else's change, found by costing it

D195 kept learned to one position per pattern because it appears in enumerations whose size is the product of their parts, and squaring a large list is not affordable. That was correct and is no longer binding.

prefix-module-learned-learned-verb-tail is the shape five of the measured names need:

learned size	candidates
12,255, as it stood this morning	12,164,987,025,000
177, after the list was reduced	2,537,649,000 - about two thirds of the whole current space

Four thousand eight hundred times cheaper, which turns "never" into "one afternoon". The reduction was made for unrelated reasons and its most valuable consequence was invisible until something costed the shapes it unlocked.

Worth stating as a general point. A vocabulary list's size is not only a coverage question, it decides which shapes can exist at all - so shrinking a list can buy more names than growing it. Nothing in the tooling said so, which is why tests/shapes.rs now prints the cost of every shape it asks for.