claimroutineinferred_dep

Some small piece carries many incidences

Claim·§2.3 Degree control and a maximizing rectangle·inside propIncidence piece with degree and expansion control

Statement (paper)

After the deletion, each remaining region meets at most t2+at^{2+a} circles, and its assigned point set is split into sets of size at most 2t1+2a2t^{1+2a}, so that the total number of pieces is at most t2−2a+o(a)t^{2-2a+o(a)}. Some piece, with vertex sets P0,Q0P_0,Q_0 and edge count e0e_0, satisfies ∣P0∣≤2t1+2a|P_0|\le 2t^{1+2a}, ∣Q0∣≤t2+a|Q_0|\le t^{2+a} and t2+2a−o(a)≤e0≤t2+2a+o(a)t^{2+2a-o(a)}\le e_0\le t^{2+2a+o(a)}, where the upper bound follows from .

In plain English

After the cutting deletion, each region meets at most t2+at^{2+a} circles and its points are split into chunks of size at most 2t1+2a2t^{1+2a}, giving at most t2−2a+o(a)t^{2-2a+o(a)} pieces in total. Some piece with vertex sets P0,Q0P_0,Q_0 has ∣P0∣≤2t1+2a|P_0|\le 2t^{1+2a}, ∣Q0∣≤t2+a|Q_0|\le t^{2+a} and between t2+2a−o(a)t^{2+2a-o(a)} and t2+2a+o(a)t^{2+2a+o(a)} incidences.

Why it's here

The previous claim shows that t4−o(a)t^{4-o(a)} incidences survive the deletion. Spreading them over at most t2−2a+o(a)t^{2-2a+o(a)} pieces forces some piece to carry at least t2+2a−o(a)t^{2+2a-o(a)} of them (pigeonhole). The Szemerédi–Trotter bound for unit circles caps every piece's count at t2+2a+o(a)t^{2+2a+o(a)}, so this piece has the claimed edge count. The next claim trims high-degree vertices in this piece to reach the degree bounds.
Classified routine:
Pigeonhole over the pieces produced by the cutting lemma, combined with the earlier claim on surviving incidences and the Szemerédi–Trotter-type bound for unit circles. This is standard bookkeeping in cutting arguments.

Sources

PaperOpen
Section
§2.3 Degree control and a maximizing rectangle
Page
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Label
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sections/01-incidence.tex:221
Leannot aligned

Phase 2 aligns this node to a Lean declaration.

Friction

  • info
    inferred_dep
    outline: "Some small piece carries many incidences" rests on claim-inc-piece-1
  • info
    inferred_dep
    outline: "Some small piece carries many incidences" rests on inc:incidence