---
license: mit
tags: [clara, reasoning, pretraining, synthetic]
---

# Clara_v4_stage3 — targeted reasoning

**172,282,390 tokens · 4 pools · pre-tokenised `uint16` bins.** Each pool is aimed at a **measured**
weakness, not a guessed one. Measured on `clara_1920_lockedmix` (d24, n_embd 1920, dense) at step
72,000, CORE corrected:

| pool | tokens | target task | measured centered score |
|---|---|---|---|
| `letter_binding_v1` | 75,499,631 | `commonsense_qa` | **−0.0625** (below chance) |
| `deduction_chains_v1` | 63,400,968 | `agi_eval_lsat_ar` | **−0.0029** |
| `dyck_ops_v1` | 19,892,808 | `bigbench_dyck_languages` | **0.1520** |
| `repeat_ops_v1` | 13,488,983 | `bigbench_repeat_copy_logic` | **0.0000** (0/32) |

Three of the model's four weakest CORE tasks; the fourth
(`bigbench_language_identification`) is deliberately unserved.

## Format
`uint16` little-endian. `BOS = 65463`, `EOS = 65464`. Tokenizer `tok_64k_singledigit`, sha256
`0c9c6d8c528d5aae542e27276ef9c48000dc32a8e3edab76071438d3be40d706`, **`Digits` pre-tokenizer stage
present**. Verify with `CLARA_TOKENIZER/verify_tokenizer.py` from `Clara_v4_stage1` before mounting.

## Dosing — for COVERAGE, not presence
Under random-offset sampling a pool served at N epochs shows only `1 − e^(−N)` of itself:
**1 ep = 63%, 3 ep = 95%, 5 ep = 99.3%.** A targeted pool must be dosed for coverage — **≥3 epochs** —
or a third of it is never drawn. On a 115.8B run that is 0.196% / 0.164% / 0.052% / 0.035%.

## ⚠️ Ruler discipline
Every pool here targets a named benchmark task and is therefore a contamination magnet.
`letter_binding_v1` and `deduction_chains_v1` carry **import-time disjointness asserts** against their
probe banks. ⛔ **`repeat_ops_v1` shares vocabulary with 5 of `repeat_copy_logic`'s 32 items** — that
is 0.156 of the task, so **a gain of ≤5/32 on that task is not evidence the pool worked.**

⛔ The eval bundle and every probe file are never training inputs. Pool/ruler crossing has happened
four times on this program; the only safe direction is to move the pool, never the ruler.

## Provenance
Entirely synthetic, generated by this lab. Items are produced **by actually solving**, never by
templating a line per input — `deduction_chains_v1` solves by constraint propagation and then
backward-slices to the inferences the answer depends on.

**Shards: 65 / 64 / 49 / 49.** Sharded so `n_shards >= world_size x 4`; with `shards[rank::world]` a pool with fewer shards than ranks leaves some ranks with **zero** shards for that lane and it is silently served at a fraction of its configured dose.