Halt without output

L0.R0.hello-world

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: #1 (historical identifier L0)
family / transform: EchoPrefix / Identity
cases: 1 case, 0 output bytes each
limits: program ≤ 256 bytes, ≤ 100000 steps/case
task summary: Load a valid program and stop cleanly.
exact contract: Registry JSON · L0.R0.hello-world

Winning program

solutions/hello-world/halt-no-output.mal · 2 bytes canonical (3 on disk) · sha256 canonical 065db44fc09e793d51fca8ee8076358e09b368b6c91e121b511f4f525d0009cb · file 887ae9f882213f03c24a9d2d2eeda1412d67682ec62b78452cd077fc187252d4

QC

Solver

name: QC (canonical)
type: canonical
metric: 1/1 case (zero-output halt), 5 seeds
attribution notes: Classic 2-byte halt-with-no-output program; carried as a golden fixture (fixtures/classic/halt_no_output.mal).

Task notes

Load a valid program and stop cleanly.

Earlier record notes

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

Zero-output conformance slot; solved by the canonical 2-byte halt program QC.

The rung requires a clean halt with zero output; the canonical 2-byte program QC satisfies it. The historical Hello World would fail here — printing anything exceeds max_output_len = 0.

Verification transcript (native VM, 3 epochs)

epoch 0 · seed 0620f21a81a0… · 1/1 cases

case	input	expected	observed	status
0	aa3e621c14f67013…			ok

epoch 1 · seed 00b0404f1503… · 1/1 cases

case	input	expected	observed	status
0	38f7014965729eb9…			ok

epoch 2 · seed 528817ff6002… · 1/1 cases

case	input	expected	observed	status
0	ba30f35b52f35334…			ok

Reproduce

git clone https://github.com/oklo/malbolge-rungs
cargo run -p harness -- verify --rung L0.R0.hello-world --program solutions/hello-world/halt-no-output.mal --epochs 3 --verbose