Negative result · failed lower-bound method

FPRD-LL-F01

One orbit's Hankel rank is not a variety lower bound

Exact statement

The rank certificate for a chosen infinite C-finite orbit in V(p)V(p) cannot be promoted to a lower bound for pp itself without proving that every admissible infinite orbit in V(p)V(p) has at least that rank.

StatusQuantifier failure isolated
External reviewNo documented external or specialist review of this FPRD exposition is recorded.

Context

The hidden-dimension problem minimizes over all admissible infinite orbits on a variety, whereas realization theory minimizes a state space for one fixed orbit.

Proof or evidence

A lower bound for one member of a set does not lower-bound the minimum over the set. The two minimizations have different quantifier order.

Verification notes

The graph construction and its rank certificate were re-read with the orbit and variety quantifiers written explicitly.

Limitations

  • This rules out an inference; it does not exhibit a lower-rank competing orbit for every graph.

Open work

Find a family for which every infinite rational C-finite orbit has growing rank, or prove a uniform compression theorem.