Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
Updated
Finite-template experiments for seven-cycles
The entry point checks the restricted algebraic identities of
two nontriangular types by exact rational
cancellation in SymPy: the boundary-minimum and interior-minimum Bernstein
expansions, the derivative-sign identity, the symmetrization density and
sum-of-squares identities, and the nonnegativity of both Bernstein
coefficient tables. Each identity is a named check through the shared
tools.Checker, so a failed identity exits nonzero, including under
python -O. It reads no input files and writes no output files. SymPy is
not a declared dependency of the root project, so run it from the
repository root with an ephemeral SymPy layer over the repository
interpreter:
uv run --no-sync --with sympy python wiki/research/erdos_809/archive/evidence/main.pyExpected runtime is under a minute; the recorded run used SymPy 1.14.0. The identities are exact statements about fixed polynomials and prove no inequality by themselves; the owning page supplies the argument that uses them.
The four scripts under util/ are exploratory searches, not evidence. No
gate runs them, they use fixed seeds and bounded samples, and their failure
to find a counterexample is not a proof of a universal inequality. They
need NumPy, SciPy and NetworkX, and the versions used for the recorded runs
were not recorded; run one from the repository root the same way, with
--with numpy --with scipy --with networkx. The three template LP searches
support the observations in random blow-ups.
| Script | Seed | Recorded scope |
|---|---|---|
c7_template_lp_search.py | 80907 | 150 templates, 2000 full-conflict LPs |
c7_template_lp_search_23.py | 80923 | 150 templates, 2000 two-plus-three LPs |
c7_template_lp_density_23.py | 80924 | Same support pool, 2000 density-maximization LPs |
c7_joint_clique_weight_search.py
is an exploratory weighted-clique search.