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Drew T
835c45905d
The hindsight-study §7 taxonomy predicts plateaus decompose into missing-transform (the "highest-value bucket and the whole point"), seed-structural, and genuine-wall. Run against real plateaus this class produced NO missing-transforms, and the answer needed no LLM. MEASURED: `length` probe, 20 targets, 1 win. tail 1/6; partial 0/12. AUTOPSY (read directly from the bytes, 3 partial plateaus): - func_8017F0C0 / func_801806C8: target has `sltiu $v0,$v0,1` = gcc's codegen for `!x`/`x==0`; the drafts wrote `(u32)(D_x ^ 1)` which emits `xori`. No local mutation crosses that. - func_8017FF90: draft stores to arg0+8, target stores to a GLOBAL. Different function. => these are WRONG DRAFTS wearing a small closeness, i.e. seed-structural, not a mutation gap. THE FIX IS THE OPPOSITE OF "ADD TRANSFORMS" — a tighter ADMISSION rule: - _drift_route: permuter only when |d|<=2 AND explains=="tail" (the shape that measurably converts). length pool 339 -> 34; permuter bucket 389 -> 84. - SIZE-MISMATCH: added a PROPORTIONAL test (|d| >= 0.5*nt). max(2,0.15*nt) is far too permissive on a tiny target — a 2-ins draft vs a 4-ins target read as a near-miss. permuter_weights needs NO extension for this class. Transferable (cookbook §60b): raising a search-closer's yield is at least as often about refusing it unreachable work as widening its mutation set. Same knife as Task-13A's targeting fix, one cut finer. Drafter idiom recorded: `sltiu rd,rs,1` => `!x`, never `x^1`. 17 unit tests green; corpus re-collected (1654 rows, closeness cross-check clean).