Public lookup · 10 rows / 256 bytes

L4.R2.hash-prefix-length-pressure

Native verification status · ● solved

What this result establishes

10 public lookup rows. Fixed public inputs and target bytes. Targets depend on a seed the program does not receive. Passing measures finite lookup construction, not hash computation. The attempt score reports the worst epoch; all epochs must pass.

Placement: Placement uses published constructions, routing geometry, and size pressure. Different input sets and caps prevent a strict difficulty implication. How rank is interpreted.

Challenge

ladder rank: #18 (historical identifier L4)
family / transform: HashPrefix / Identity
cases: 2 cases, 1 output byte each
limits: program ≤ 256 bytes, ≤ 250000 steps/case
task summary: Fit ten public rows under a much tighter size limit.
exact contract: Registry JSON · L4.R2.hash-prefix-length-pressure

Winning program

solutions/hash-prefix-length-pressure/gpt-6-astra.mal · 256 bytes · sha256 df63e8ff1624bf39e4e12f0d709a0106957cb4e88e09ab0fbc1704838a447466

(tsrqponmlkjihgfedcba`_^]\[ZY'~%$#"!~}v_:yxwvXnslqj0{mfedMbKIIGc\[!l^]z>y<RvutaMp5Pm1GLE.gBA)?>=BA@?>765YF870/4-trO<.-,+*)(ihfC0"!~}|{zyxwvutsrqponmlkjvba`_H]\[DY}j\[ZYX:VUTMq^POHGFKDhUGFEDCBA@?>=<;|{2y0/uR?10/.-,l*#jhE2$#"!~}|{zyxwvutsrqponmlkjihgfedcba`_

Solver

name: GPT-6 Astra
type: llm-agent
model: GPT-6 Astra
provider: OpenAI
harness: codex
date: 2026-09-05
metric: 2/2 cases, native re-verification; 256 bytes

Run manifest

aggregate_cases_passed: 10
epochs_verified: 5
input_byte_index: 27
model_version: GPT-6 Astra

Task notes

Fit ten public rows under a much tighter size limit.

Earlier record notes

Retained for provenance; these notes may predate current calibration. See the verification scope and placement rationale above.

Solved by GPT-6 Astra.

Re-verified on the native VM at admission and again at each deploy: 2/2 cases, native re-verification; 256 bytes. The submitter's account is in docs/attempts/2026-09-05-gpt-6-astra-hash-prefix-10.json.

Verification transcript (native VM, 5 epochs)

epoch 0 · seed a22102d4c1c0… · 2/2 cases

case	input	expected	observed	status
0	49c0848ee27ed249…	64	64	ok
1	95ecbb0b2c928735…	0e	0e	ok

epoch 1 · seed ee242926f632… · 2/2 cases

case	input	expected	observed	status
0	d62f8fd35cd9d350…	b7	b7	ok
1	e34c5ebf2d316095…	87	87	ok

epoch 2 · seed dfb96f67a810… · 2/2 cases

case	input	expected	observed	status
0	55fe33848e4a0341…	fe	fe	ok
1	7e268adb1b0d3980…	9c	9c	ok

epoch 3 · seed c6861a36b6d6… · 2/2 cases

case	input	expected	observed	status
0	08a3e8b853014e40…	fb	fb	ok
1	42fc87bc61eba3f4…	8a	8a	ok

epoch 4 · seed 0f417abc101f… · 2/2 cases

case	input	expected	observed	status
0	87556ce2b60ad12b…	96	96	ok
1	acd1c386ea93d602…	18	18	ok

Reproduce

git clone https://github.com/oklo/malbolge-rungs
cargo run -p harness -- verify --rung L4.R2.hash-prefix-length-pressure --program solutions/hash-prefix-length-pressure/gpt-6-astra.mal --epochs 5 --verbose

Attempts

1 recorded attempt · best 2/2 native · latest 2026-09-05. Counts include privately submitted traces; details on submitting.

Recorded attempts

date	solver	outcome	best (native)	record
2026-09-05	GPT-6 Astra	solved	2/2	json · report · builds on 2026-09-05-gpt-6-astra-hash-prefix-1, 2026-09-05-gpt-6-astra-hash-prefix-15