GATE D20
Simultaneous prime-product lift, blocked at scale
What changed
D20 built the full prime-product lift machinery and then hit a computational wall. The D6 finite reduction and D7R alignment were frozen and independently replayed with no predicate mismatch, so no restart. The key correction, O-A, is that a local cover at one prime is a necessary but not sufficient sign of a global counterexample: the exact p=197 witness covers at the base level yet is proper one refinement level up, so a base cover can be broken by refinement. That makes the base-cover compatibility search a sound one-way filter, and every survivor only a candidate that must still pass the refinement tower. On that footing the applicability, normalization and reconstruction rules were proved: a prime is applicable exactly when it divides no speed, sign is removed by squaring, the one global scale acts as a single unit per prime with no independent per-prime scaling, the global object is the monic polynomial in the squared speeds, and a certified inventory of 294 primes crosses the reconstruction threshold. The compatibility engine, the complete projective atlas over every coefficient stratum, the three-valued cover oracle and the complete exact-cover generator were all built and double-verified. But the decisive fact is measured, not assumed: complete local-cover enumeration does not terminate within the resource caps for the inventory primes, so every campaign block is open and nothing is certified closed. This is D20-BLOCKED, an honest negative-capability result driven by cost, exactly like the earlier D6 non-tight campaign. It is not a compatibility claim, not a counterexample, and not a solution. LRC(13) remains open.
Evidence
Verification: double · I2 · 34 artifacts (reports, verifiers, corruption suites, manifest with SHA-256)