Echo two bytes

L1.R1.echo-2

Native verification status · ● solved

What this result establishes

Public example suite. Fixed public examples, with exact output and halt required. Canonical copying solutions may be more general than the tested suite; the suite alone does not establish that.

Placement: Verified canonical or tool baseline. Similar slots are retained for historical continuity. How rank is interpreted.

Challenge

ladder rank: #5 (historical identifier L1)
family / transform: EchoPrefix / Identity
cases: 1 case, 2 output bytes each
limits: program ≤ 128 bytes, ≤ 256 steps/case
task summary: Copy two bytes in order.
exact contract: Registry JSON · L1.R1.echo-2

Harness documentation

Winning program

solutions/echo/echo-2.mal · 5 bytes · sha256 385b4edf9e49a9cd015866887b79f5c18c82ba9d7b6ff6ae3ab899cd3433d9c7

ubs`M

Solver

name: HeLL-Lite (tool)
type: tool
harness: tools/hell_lite compile-linear (deterministic straight-line template)
metric: 1/1 case, 5 seeds
attribution notes: First-use opcode encoding of the straight-line IN/OUT sequence; each address has exactly one printable byte per opcode.

Task notes

Copy two bytes in order.

Earlier record notes

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

Echo the first 2 input bytes; 5-byte straight-line program.

Verification transcript (native VM, 3 epochs)

epoch 0 · seed 99a599788c60… · 1/1 cases

case	input	expected	observed	status
0	68046957c1e9cc2e…	6804	6804	ok

epoch 1 · seed 7ba7077edc2a… · 1/1 cases

case	input	expected	observed	status
0	bd52e1a35813cf17…	bd52	bd52	ok

epoch 2 · seed 126b963038d0… · 1/1 cases

case	input	expected	observed	status
0	43dd794d0806a752…	43dd	43dd	ok

Reproduce

git clone https://github.com/oklo/malbolge-rungs
cargo run -p harness -- verify --rung L1.R1.echo-2 --program solutions/echo/echo-2.mal --epochs 3 --verbose