Revert "coloring_nested_tire_graphs: clarify uniqueness-failure figure"

This reverts commit 6c6d1eac94.
This commit is contained in:
2026-05-26 23:48:54 -04:00
parent 32dd4d3553
commit b2e1239c06
4 changed files with 33 additions and 43 deletions
@@ -1,6 +1,6 @@
\relax
\@writefile{toc}{\contentsline {paragraph}{Why low-side faces break uniqueness.}{1}{}\protected@file@percent }
\@writefile{toc}{\contentsline {paragraph}{The coverage gap.}{2}{}\protected@file@percent }
\@writefile{toc}{\contentsline {paragraph}{The coverage gap.}{1}{}\protected@file@percent }
\@writefile{toc}{\contentsline {paragraph}{Resolution.}{2}{}\protected@file@percent }
\@writefile{toc}{\contentsline {paragraph}{Setup.}{2}{}\protected@file@percent }
\@writefile{toc}{\contentsline {paragraph}{The low-side face of $H_1$.}{2}{}\protected@file@percent }
@@ -1,4 +1,4 @@
This is pdfTeX, Version 3.141592653-2.6-1.40.24 (TeX Live 2022) (preloaded format=pdflatex 2022.10.5) 26 MAY 2026 23:36
This is pdfTeX, Version 3.141592653-2.6-1.40.24 (TeX Live 2022) (preloaded format=pdflatex 2022.10.5) 26 MAY 2026 23:33
entering extended mode
restricted \write18 enabled.
%&-line parsing enabled.
@@ -587,10 +587,10 @@ File: umsb.fd 2013/01/14 v3.01 AMS symbols B
[4] [5]
(./boundary_cut_tire.aux) )
Here is how much of TeX's memory you used:
14740 strings out of 478268
301161 string characters out of 5846347
568755 words of memory out of 5000000
32695 multiletter control sequences out of 15000+600000
14739 strings out of 478268
301145 string characters out of 5846347
571661 words of memory out of 5000000
32694 multiletter control sequences out of 15000+600000
482413 words of font info for 79 fonts, out of 8000000 for 9000
1141 hyphenation exceptions out of 8191
84i,6n,89p,452b,713s stack positions out of 10000i,1000n,20000p,200000b,200000s
@@ -617,7 +617,7 @@ ocal/texlive/2022/texmf-dist/fonts/type1/public/amsfonts/cm/cmti8.pfb></usr/loc
al/texlive/2022/texmf-dist/fonts/type1/public/amsfonts/cm/cmtt10.pfb></usr/loca
l/texlive/2022/texmf-dist/fonts/type1/public/amsfonts/symbols/msbm10.pfb></usr/
local/texlive/2022/texmf-dist/fonts/type1/public/cm-super/sfrm1095.pfb>
Output written on boundary_cut_tire.pdf (5 pages, 251070 bytes).
Output written on boundary_cut_tire.pdf (5 pages, 249957 bytes).
PDF statistics:
134 PDF objects out of 1000 (max. 8388607)
82 compressed objects within 1 object stream
@@ -36,49 +36,39 @@ $H_{d-1}$ edges).
\begin{center}
\begin{tikzpicture}[scale=0.95]
\begin{scope}[on background layer]
% Y (outside H_{d-1}): light yellow
\fill[yellow!22] (-4.4, -3.0) rectangle (4.4, 3.0);
% X (between H_{d-1} and H_d): light cyan
\fill[cyan!18] (0, 0) circle (2.4);
% A (inside H_d): white
\fill[white] (0, 0) circle (1.0);
\end{scope}
\draw[blue, very thick] (0, 0) circle (2.4);
\draw[orange!90!black, very thick] (0, 0) circle (1.0);
% Mark "face B = X Y" with a dashed red boundary just outside H_d
\draw[red, thick, dashed] (0, 0) circle (1.08);
\node[orange!90!black] at (0, 0) {\small $A$};
\node[blue] at (1.05, 2.25) {\small $H_{d-1}$};
\node[orange!90!black] at (-1.05, -0.45) {\small $H_d$};
\node[fill=cyan!18, inner sep=1pt] at (1.6, 1.35) {\small face $X$ of $H_{d-1}$};
\node[fill=yellow!22, inner sep=1pt] at (3.2, 2.55) {\small face $Y$ of $H_{d-1}$};
\node[red] at (-2.95, 1.45) {\small face $B$ of $H_d$};
\node[red] at (-2.95, 1.15) {\small (= everything};
\node[red] at (-2.95, 0.85) {\small outside red dashed)};
\draw[->, red, thick] (-1.95, 1.0) -- (-1.15, 1.0);
\draw[->, red, thick] (-1.95, 1.0) .. controls (-2.3, 1.6) and (-3.1, 2.4) .. (-3.5, 2.7);
\begin{scope}[on background layer]
\fill[red!10] (-4.2, -3.0) rectangle (4.2, 3.0);
\fill[white] (0, 0) circle (1.0);
\end{scope}
\node[blue] at (-1.05, 2.25) {\small $H_{d-1}$};
\node[orange!90!black] at (-0.75, -0.55) {\small $H_d$};
\node[blue, fill=white, inner sep=1.5pt] at (0, 0.4) {\small face $A$};
\node[blue, fill=white, inner sep=1.5pt] at (0, -0.0) {\small (high-side)};
\node[red] at (-3.4, 0.2) {\small face $B$ of $H_d$};
\node[red] at (-3.4, -0.1) {\small (low-side)};
\node[gray] at (2.3, 0.0) {\small face $X$ of $H_{d-1}$};
\node[gray] at (2.3, -0.3) {\small (between cycles)};
\node[gray] at (3.1, 2.45) {\small face $Y$ of $H_{d-1}$};
\node[gray] at (3.1, 2.15) {\small (outside)};
\draw[->, gray, thick] (2.45, 2.25) -- (2.0, 1.85);
\draw[->, gray, thick] (1.8, 0.0) -- (1.55, -0.0);
\end{tikzpicture}
\end{center}
Here face $B$ of $H_d$ (low-side) is \emph{everything outside the
dashed red boundary} --- i.e.\ the union of the cyan annulus and the
exterior yellow region. This is a single connected face of
$\mathbb{R}^2 \setminus H_d$ (the red boundary is just the inner
edge of $H_d$; from $B$'s perspective there is no separating curve
out at $H_{d-1}$).
But the two \emph{faces of $H_{d-1}$} are distinct regions:
The red region is face $B$ (low-side of $H_d$): a single connected
region of $\mathbb{R}^2 \setminus H_d$. But $B$ is split by the
$H_{d-1}$ cycle into:
\begin{itemize}
\item Face $X$ of $H_{d-1}$: the cyan annulus between $H_d$ and
$H_{d-1}$. It is a proper subset of $B$ (the yellow exterior
lies outside $X$).
\item Face $Y$ of $H_{d-1}$: the yellow exterior region. Also a
proper subset of $B$ (the cyan annulus lies outside $Y$).
\item Face $X$ of $H_{d-1}$: the annular region between $H_d$
and $H_{d-1}$.
\item Face $Y$ of $H_{d-1}$: the exterior of $H_{d-1}$ (where the
pendants live).
\end{itemize}
So $X \subsetneq B$ and $Y \subsetneq B$, but $B \not\subseteq X$
and $B \not\subseteq Y$. Neither $X$ nor $Y$ contains all of $B$,
so $B$ has no unique parent face in $H_{d-1}$. This is the
Neither $X$ nor $Y$ contains \emph{all} of $B$ --- they each contain
a piece. If we tried to make $B$ a child of some unique
$H_{d-1}$ face in the tree, no such parent exists. This is the
``uniqueness step'' that fails for low-side faces.
By contrast, face $A$ (high-side, inside the inner cycle) sits