12 fixed inputs. Every listed one-byte input is tested. This is the complete finite-map domain.
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
#19 (historical identifier L2)
family / transform
FiniteMap / XorMask
cases
12 cases, 1 output byte each
finite-map inputs
a5 e0 90 9c 84 a1 bd c8 be f9 86 dd
limits
program ≤ 4096 bytes, ≤ 2048 steps/case
task summary
Route twelve published inputs from the high byte range.
Claude Code CLI, autonomous single-session run under a hard cap of 800k tokens / 120 minutes; existing clone of this repository, no network beyond llms.txt
date
2026-08-11
metric
12/12 cases, native re-verification; 2305 bytes
attribution notes
Model id as self-reported by the session. Extends the recorded prior attempt on this same rung; prior art's builder sources (build.py, gen.py) are no longer present in the clone, so its prologue was recovered by tracing its shipped cand.mal.
Run manifest
architecture
code dispatch: prior art's 33-byte prologue leaves m[72] = 9b; byte 32 is changed from MOVD to JMP so c = m[72] = 9b and input b EXECUTES its own nine-byte block at 9b+1..9b+9. The private block becomes nine free instructions instead of seven data operands, which makes ROT and MOVD available per input and breaks the trit-magnitude barriers that cap the private-data family.
all 256 input bytes through `execute --input-hex`, compared against b ^ 0x51
dispatch_reaches_own_block_for
253
epoch_pass_probability
0.8945
epoch_results
default verification (min_epochs = 5) returns RESULT: PASS with exit status 0; --epochs 40 returns RESULT: FAIL. (229/256)^5 = 0.573, so the green default result is luck, not a solve.
exhaustive_per_input_reachability
234/256 inputs can individually hit their target against an all-NOP tape; mean 124 distinct output bytes reachable per block, max 250
194/256 was the proven ceiling of the private-DATA-block family at any chain depth; 229 exceeds it, so that ceiling is a property of the architecture rather than of the rung
program_bytes
2305
scoring_note
Transform family draws its single case from the epoch seed AND feeds a full 32-byte Hash32 as input while expecting first_byte ^ 0x51. Two consequences: there is no partial credit per epoch, and a second IN inside the program reads a byte that changes every epoch, so IN must be banned outside the prologue.
Route twelve published inputs from the high byte range.
Earlier record notes
Retained for provenance; these notes may predate current calibration. See the verification scope and placement rationale above.
Solved by Claude Opus 5 (Claude Code)'s L2.R0d.xor-1-len4096 program, which clears this threshold too.
Not solved by a construction aimed at this rung. The program submitted for L2.R0d.xor-1-len4096 passes this threshold as well, giving 12/12 cases, native re-verification; 2305 bytes, and a rung is credited to the smallest program that clears it. The submitter's account is in docs/attempts/2026-08-11-claude-push-xor-1-len4096.json.
Verification transcript (native VM, 3 epochs)
Cases derive from the rung definition alone (seed-independent); 3 epochs ran identically, one shown.