Tim Lingo
8f3a478771
CAUGHT BY A/B, AND ONLY BY A/B. The previous commit's receipt_strip assumed the receipt is
always TERMINAL and cut everything from the marker onward. It is not always terminal: once
receipt_rule told the model what [[RECEIPT ...]] means, the model sometimes LED with one and
wrote the answer underneath. Cutting at the marker then deleted the entire answer and the
turn returned {"error":"no response"}.
MEASURED, same prompt (two web searches, cited prose), fresh session each run:
round-7 brain 4 / 4 answered (471, 473, 473, 544 chars)
round-8 brain 2 / 7 answered (five {"error":"no response"})
This looked exactly like a flaky model. It was not — it was mine. Running the two brains
side by side on the same prompt is the only reason it was found, and it is the reason the
A/B is now part of how this class gets tested.
AFTER THE FIX, same protocol:
round-7 brain 4 / 4 (473, 473, 473, 544)
round-8 brain 4 / 4 (657, 657, 657, 673)
THE FIX: remove the [[...]] span and keep BOTH sides, instead of truncating at the marker.
An unterminated marker at position 0 is left completely alone — no rule about receipts is
worth erasing an answer over. Bounded four-pass loop rather than a conditional exit, because
rebinding the counter inside an if-expression is the block-expression shape that miscompiles
integer arithmetic under this elc (BUG-PLAINCHAT-1). Verified in the generated C:
str_slice(rest, (e + 2), str_len(rest)) <- integer addition, correct
el_str_concat(head, tail) <- string concat, correct
and zero el_str_concat(<ident>, str_len(...)) sites across all 49 modules.
SEAM PROOF (FIX C) rides on the same runs — a real two-search cited answer, inspected byte
by byte, in BOTH failure directions:
missing separator (the round-7 "to.Good", bytes 77 2e 47): 0 hits. Sentence boundaries
measure 2e 20 4d — "." SPACE "M".
over-separation (a cited sentence shattered across paragraphs): 0 hits. The answer is one
continuous paragraph with its sentences intact, which is the direction a blanket
separator would have broken.
BUILT: sha256 77115f2733e794c5bc4ad1f55b1acaf658f8f4a91cccd423a2d633d94a726cbc
Refs neuron#109
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>