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fd-formalization

A complete Lean 4 + Mathlib proof that the \((u,v)\)-flowers have fractal dimension \(\log(u+v)/\log u\), up to box-counting dimension.

Get Started Theorems


What it proves

For \(1 < u \leq v\):

Theorem Statement File
F1 --- log-ratio limit \(\displaystyle\lim_{g \to \infty} \frac{\log N_g}{\log L_g} = \frac{\log(u+v)}{\log u}\), for the vertex count \(N_g\) and hub distance \(L_g\) defined by recurrences FlowerDimension.lean
F2 --- hub distance the explicit flower graph on \(\mathrm{Fin}\,N_g\) has distance \(L_g = u^g\) between its hubs, the indices 0 and 1 FlowerConstruction.lean
F3 --- graph dimension so the flower graphs themselves have log-ratio dimension \(\log(u+v)/\log u\) FlowerGraphDimension.lean
F4 --- box counting the flower graphs have box-counting dimension \(\log(u+v)/\log u\), along every scale sequence \(\ell_g\) with \(\operatorname{diam} G_g / \ell_g \to \infty\) FlowerBoxDimension.lean

Rozenfeld et al. (2007) identify this limit with the box-counting dimension \(d_B\); F4 proves that identification for the explicit graphs.

The library builds with no sorry, and the 78 declarations checked in Verify.lean use only propext, Classical.choice and Quot.sound.

Documentation

Section Contents
Quickstart Build and verify
Proof Strategy Squeeze argument for F1; cells and box counting for F4
Graph Construction F2 and F3: gadgets, the distance proof
Theorems Catalog by file
Roadmap What is done, and the scope
Prior art The priority claim and the search behind it