Pith Number

pith:VBJO4ENL

pith:2026:VBJO4ENLCH2POJSNTJTSR2I5I5

not attested not anchored not stored refs pending

Unleashing Implicit Rewards: Prefix-Value Learning for Distribution-Level Optimization

Hongzhan Chen, Lifu Huang, Qifan Wang, Shiping Gao, Xiaojun Quan

Training a prefix value function on outcome labels alone produces reliable step rewards for reasoning chains.

arxiv:2604.13197 v2 · 2026-04-14 · cs.CL

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\pithnumber{VBJO4ENLCH2POJSNTJTSR2I5I5}

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Record completeness

1 Bitcoin timestamp

2 Internet Archive

3 Author claim open · sign in to claim

4 Citations open

5 Replications open

✓ Portable graph bundle live · download bundle · merged state

The bundle contains the canonical record plus signed events. A mirror can host it anywhere and recompute the same current state with the deterministic merge algorithm.

Claims

C1strongest claim

IPVRM substantially improves step-verification F1 on ProcessBench. Building on these calibrated prefix values, we further propose Distribution-Level RL (DistRL), which ... consistently improves downstream reasoning once paired with IPVRM.

C2weakest assumption

That a prefix-conditioned value function trained only on outcome labels can accurately estimate the probability of eventual correctness and that TD differences between prefixes yield faithful local step-quality signals without systematic bias or additional verification.

C3one line summary

IPVRM learns prefix values to produce reliable step rewards from sequence outcomes using TD learning, enabling distribution-level RL that improves reasoning when paired with calibrated rewards.

Receipt and verification

First computed	2026-05-29T01:05:09.674642Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

a852ee11ab11f4f7264d9a6728e91d476eccd7c1cc2f8701b4911e8aff704579

Aliases

arxiv: 2604.13197 · arxiv_version: 2604.13197v2 · doi: 10.48550/arxiv.2604.13197 · pith_short_12: VBJO4ENLCH2P · pith_short_16: VBJO4ENLCH2POJSN · pith_short_8: VBJO4ENL

Agent API

Resolver JSON Graph JSON Events JSON Schema Signing key

Verify this Pith Number yourself

curl -sH 'Accept: application/ld+json' https://pith.science/pith/VBJO4ENLCH2POJSNTJTSR2I5I5 \
  | jq -c '.canonical_record' \
  | python3 -c "import sys,json,hashlib; b=json.dumps(json.loads(sys.stdin.read()), sort_keys=True, separators=(',',':'), ensure_ascii=False).encode(); print(hashlib.sha256(b).hexdigest())"
# expect: a852ee11ab11f4f7264d9a6728e91d476eccd7c1cc2f8701b4911e8aff704579

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "7415e0eee79e184f672cd2e44a35ed2b65ac96f4b83fd716c4bd4ce847583a17",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "cs.CL",
    "submitted_at": "2026-04-14T18:19:54Z",
    "title_canon_sha256": "971a620fc25e137939b2e5d36dcebc9cf752b774644f869fc8ae1b119bbd5e57"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2604.13197",
    "kind": "arxiv",
    "version": 2
  }
}