The geometry of Section~\ref{sec:p0-aes} is developed on the basic model, which is complete and unpunctured: $\mathfrak E_0$ has no point at which the arithmetic structure fails. (The one-puncture model $\mathfrak E_1$ of Example~\ref{ex:p0-e1-model} already leaves the regular category, and is the case this chapter generalizes.) This chapter develops the opposite situation through explicit punctured models and the vocabulary proposed for them. Its exact local constructions are kept distinct from a register of six computed witnesses, each with its own status. The finite-type construction and reconstruction interface follow in Section~\ref{sec:p0-compactification}. The interpretive reading of those witnesses --- the language of tearing --- is presented as a structural proposal, and Subsection~\ref{subsec:p0-holed-nonclaims} lists what is not established. \subsection{Punctured arithmetic expression spaces} \label{subsec:p0-holed-definition} \begin{definition}[Punctured arithmetic expression space] \label{def:p0-punctured-aes} Let $\overline M$ be an oriented smooth surface, let $S\subset\overline M$ be a finite set of points, and put $M=\overline M\setminus S$. Suppose given a smooth Riemannian metric $g$ on $M$, a function $a:M\to\mathbb R$ that is smooth on $M$, and constants $\mu\ne0$, $\lambda$, such that \begin{enumerate} \item $(M,g,a;\mu,\lambda)$ is a regular AES in the sense of Definition~\ref{def:regular-aes}, and \item for every $p\in S$, no neighbourhood $U$ of $p$ in $\overline M$ admits extensions of $g|_{U\cap M}$ and $a|_{U\cap M}$ to smooth data $\widetilde g,\widetilde a$ on $U$ for which $(U,\widetilde g,\widetilde a;\mu,\lambda)$ is a regular AES. \end{enumerate} Then $(\overline M,S,g,a;\mu,\lambda)$ is called a \emph{punctured arithmetic expression space}, and the points of $S$ are its \emph{punctures}. When $|S|=k$ we write $\mathfrak E_k$ for it, in the descriptive sense of Convention~\ref{conv:p0-model-labels}. \end{definition} The ambient surface and the data are deliberately separated: the regular AES is given only on the punctured surface $M$, so that condition (ii) is a genuine requirement rather than a contradiction. A puncture is not any point that has been deleted, but a point at which the regular structure genuinely cannot be continued. This is the finite-point case of the singular arithmetic expression space of Paper~I; the general singular theory, the classification of singular germs, and everything concerning tubes, braids, and knot invariants belong to Paper~I and Paper~III. The notion is specialized here for one reason only: the arithmetic motions of Subsection~\ref{subsec:p0-point-paths} are defined on the punctured surface, and the question of what happens to them at a puncture is a question about AES. The first example is the one-puncture model of Example~\ref{ex:p0-e1-model}: the unit disc with the complete Poincar\'e metric and the radial assignment $a_{\mathbb D}=\frac{2\mu}{\lambda}\rho/(1-\rho^2)$, whose metric extends smoothly across the centre while the assignment does not. There $S=\{0\}$ and the regular locus is $\mathbb D\setminus\{0\}$. Two features of that example are worth recording here, because they are typical of punctured models. First, the extended metric is complete on $\mathbb D$ while its restriction to $\mathbb D\setminus\{0\}$ is \emph{not} complete: the puncture is at finite distance from every interior point, so the incompleteness is caused by the deletion and not by the geometry. Second, the assignment has a finite limit at the puncture (here $0$) but no $C^1$ extension, so the failure is a failure of differentiability rather than of continuity. Both statements are verified in Paper~I together with the model. \subsection{The local shape of a puncture} \label{subsec:p0-holed-tangent-cone} A puncture is not merely a missing point; at least in the example that has been computed in detail, it carries a definite local shape. The following statement is exact. \begin{proposition}[Tangent cone of the four limiting circles] \label{prop:p0-puncture-tangent-cone} Fix $\rho>0$ and consider the four circles through the origin \[ C_\pm:\ x^2+y^2\mp2\rho y=0, \qquad D_\pm:\ x^2+y^2\mp2\rho x=0 . \] Write $S_2=x^2+y^2$ and let \[ P=\bigl(S_2^2-4\rho^2y^2\bigr)\bigl(S_2^2-4\rho^2x^2\bigr) \] be the defining polynomial of their union. Then \[ P=S_2^4-4\rho^2S_2^3+16\rho^4x^2y^2 , \] so the lowest-degree homogeneous part of $P$ is $16\rho^4x^2y^2$. Consequently the tangent cone of the union at the origin is \[ (xy)^2=0 , \] that is, the two coordinate axes, each with multiplicity two. \end{proposition} \begin{proof} The four circles are $S_2=\pm2\rho y$ and $S_2=\pm2\rho x$, whose defining polynomials are $S_2^2-4\rho^2y^2$ and $S_2^2-4\rho^2x^2$ respectively; the product is $P$. Expanding, \[ \bigl(S_2^2-4\rho^2y^2\bigr)\bigl(S_2^2-4\rho^2x^2\bigr) =S_2^4-4\rho^2S_2^2(x^2+y^2)+16\rho^4x^2y^2 =S_2^4-4\rho^2S_2^3+16\rho^4x^2y^2 , \] since $S_2^2(x^2+y^2)=S_2^3$. The terms have degrees eight, six, and four, so the lowest-degree part is $16\rho^4x^2y^2$, whose zero set is $xy=0$ counted twice. \end{proof} Two remarks, both used below. First, the two circles of the same family are tangent at the origin, so the origin is a degenerate point of each family, while circles of different families cross there with tangent lines $x=0$ and $y=0$; the tangent cone is the union of those two lines. Second, the tangent cone is \emph{reducible with multiplicity}: it is the square of a product of two distinct linear forms. The computation is recorded in the exploration register of the programme \cite{Yuan2026AEGHoleRegister}; the identity above is verified here directly. \subsection{An explicit punctured model with four zero branches} \label{subsec:p0-four-circle-model} The review of this paper observed, correctly, that the tangent cone above was a statement about a curve configuration with no arithmetic expression space attached to it. The gap is now closed: the configuration is exactly the zero locus of an explicit punctured AES. We need one general fact first. \begin{lemma}[The gradient never vanishes in a regular AES] \label{lem:p0-gradient-nonvanishing} In a regular AES $\mathfrak E=(M,g,a;\mu,\lambda)$ one has $\nabla a\ne0$ everywhere on $M$; indeed $|\nabla a|_g^2=\mu^2+\lambda^2a^2\ge\mu^2>0$. Hence, when $M$ is boundaryless, \emph{every} level set of $a$ is a smooth embedded curve. The regular-zero theorem of Paper~I is the case of level zero. \end{lemma} \begin{proof} Both sides of the eikonal identity are non-negative and the right-hand side is at least $\mu^2>0$, so $\nabla a$ does not vanish. The regular-value theorem then applies at every level, not only at $0$. \end{proof} The next theorem gives a conditional answer to the canonicality question. Both smooth extension of the assignment and extension of the conformal background are required. The latter hypothesis repairs the statement printed in the September 22 version: constructing a new AES metric does not by itself extend the prescribed metric. \begin{theorem}[Critical punctures with an extending conformal background] \label{thm:p0-punctures-are-critical} Let $(\overline M,S,g,a;\mu,\lambda)$ be a punctured AES in the sense of Definition~\ref{def:p0-punctured-aes}, and suppose that $a$ extends to a smooth function $\widetilde a$ on $\overline M$. Suppose in addition that, near each $p\in S$, the given metric $g$ is conformal on $U\setminus S$ to a smooth Riemannian metric $g_0$ on a neighbourhood $U$ of $p$, with $g_0$ non-degenerate at $p$. Then \begin{equation}\label{eq:p0-punctures-are-critical} S=\bigl\{p\in\overline M:\ d\widetilde a(p)=0\bigr\} . \end{equation} Within this conformal-background class, the puncture set is determined by the assignment and its cardinality is the number of critical points of $\widetilde a$ in $\overline M$. \end{theorem} \begin{proof} For the inclusion $S\subseteq\{d\widetilde a=0\}$, let $p\in S$ and suppose $d\widetilde a(p)\ne0$. Use the extending background metric $g_0$ supplied by the hypothesis on a neighbourhood $U$ of $p$. Writing $g=f g_0$ on $U\setminus S$, the eikonal identity forces \[ f=\frac{|d\widetilde a|_{g_0}^2}{\mu^2+\lambda^2\widetilde a^2}. \] Thus the extension constructed below agrees with the \emph{given} metric. After shrinking $U$ we have $|d\widetilde a|^2_{g_0}>0$ on $U$, because $|d\widetilde a|^2_{g_0}$ is continuous and positive at $p$, and also $\mu^2+\lambda^2\widetilde a^2>0$ on $U$, because $\mu\ne0$. Define \[ \widetilde g=\frac{|d\widetilde a|_{g_0}^2}{\mu^2+\lambda^2\widetilde a^2}\,g_0 \qquad\text{on }U . \] Then $\widetilde g$ is a smooth Riemannian metric on $U$, and \[ |d\widetilde a|^2_{\widetilde g} =\frac{\mu^2+\lambda^2\widetilde a^2}{|d\widetilde a|_{g_0}^2} \,|d\widetilde a|_{g_0}^2 =\mu^2+\lambda^2\widetilde a^2 , \] so $(U,\widetilde g,\widetilde a;\mu,\lambda)$ is a regular AES extending $(g,a)$ across $p$. This contradicts condition (ii) of Definition~\ref{def:p0-punctured-aes}. Hence $d\widetilde a(p)=0$. For the reverse inclusion, let $p\in\overline M$ with $d\widetilde a(p)=0$ and suppose $p\notin S$. Then $p\in M$ and the eikonal identity at $p$ reads \[ 0=|da(p)|_g^2=\mu^2+\lambda^2a(p)^2\ge\mu^2>0 , \] a contradiction. Hence $p\in S$. \end{proof} \begin{remark}[The hypothesis is active] \label{rem:p0-puncture-hypothesis} The theorem requires the assignment to extend smoothly. The isolated-zero disc model imported from Paper~I (Example~\ref{ex:p0-e1-model}) does not satisfy the hypothesis: there the metric extends smoothly across the centre while the assignment is only continuous, and not $C^1$, so $d\widetilde a$ does not exist at the puncture and \eqref{eq:p0-punctures-are-critical} has no meaning. The two verified punctured models are therefore of different kinds: in the disc model the \emph{assignment} fails at the puncture, while in the model below the assignment is smooth everywhere and the \emph{metric} is what cannot be non-degenerately extended. The critical-set conclusion applies to the second kind only with the theorem's extending-conformal-background hypothesis. Without it even a smoothly extending assignment need not determine the punctures. For example, on a punctured disc, $a=x$, $\mu=1$, $\lambda=0$, and \[ g=dx^2+(x^2+y^2)^{-1}dy^2 \] satisfy $|da|_g^2=1$, while $g$ cannot extend at the origin and $da$ never vanishes. In every smoothly extending case only $\operatorname{Crit}(\widetilde a)\subseteq S$ holds without further hypotheses. \end{remark} \begin{theorem}[A punctured AES whose zero locus is the four-circle configuration] \label{thm:p0-four-circle-model} Fix $\rho>0$ and $00$ on $M$ and $|\nabla a|^2$ is smooth, so $g$ is smooth and positive definite. Its eikonal identity is immediate: \[ |\nabla a|_g^2 =\frac{\mu^2+\lambda^2a^2}{|\nabla a|^2}\,|\nabla a|^2 =\mu^2+\lambda^2a^2 . \] We must also check that $\nabla a$ does not vanish on $M$, so that the conformal factor is strictly positive there. Suppose $\nabla P=0$ at a point of $\overline M$. If $x=0$ then $S_2=y^2>0$ at a punctured point and $f(0)=y^4(y^2-3\rho^2)$, which is nonzero because $y^2=S_2r$, as one checks by solving $S_2=2\rho y$, $S_2=-2\rho x$ or $S_2=2\rho y$, $S_2=2\rho x$. Hence the zero locus in $\overline M$ consists of four arcs, two tangent to the $x$-axis and two to the $y$-axis, meeting only at the origin --- which is exactly the tangent cone computed in Proposition~\ref{prop:p0-puncture-tangent-cone}. \emph{(3)} Let $U$ be a neighbourhood of the origin and let $\widetilde g$, $\widetilde a$ be smooth extensions to $U$ of $g|_{U\cap M}$ and $a|_{U\cap M}$ for which $(U,\widetilde g,\widetilde a;\mu,\lambda)$ is a regular AES. Since $\widetilde a$ is continuous on $U$ and agrees with $a$ off the origin, while $a$ extends continuously to the origin with value $P(0)=0$, we have $\widetilde a(0)=0$, and $\nabla\widetilde a(0)=\nabla a(0)=0$ because $a$ is smooth on $\overline M$. Evaluating the eikonal identity at the origin by continuity gives \[ 0=\widetilde g^{ij}(0)\,\partial_i a(0)\,\partial_j a(0) =\mu^2+\lambda^2a(0)^2=\mu^2\ne0 , \] a contradiction. So no such extension exists, which is condition (ii) of Definition~\ref{def:p0-punctured-aes}. (Equivalently: by Lemma~\ref{lem:p0-gradient-nonvanishing} a regular AES has no critical point of its assignment, whereas the origin is a critical point of $P$.) \emph{(4)} Conditions (i) and (ii) of Definition~\ref{def:p0-punctured-aes} are (1) and (3), so the tuple is a punctured AES. By (2) its zero locus is the four-circle configuration, and by the local structure computed there the four arcs meet only at the puncture. \emph{(5)} On the $x$-axis and away from the origin, $\partial_yP=0$ and $f(0)=x^4(x^2-3\rho^2)$, so $|\nabla P|=8|x|\,|f(0)|=8|x|^5|3\rho^2-x^2|$, which is $24\rho^2|x|^5+O(|x|^7)$ as $x\to0$. Hence along the axis \[ \sqrt{g_{xx}}\;dx =\frac{|\nabla P|}{\sqrt{\mu^2+\lambda^2P^2}}\,dx =\frac{24\rho^2}{|\mu|}\,|x|^5\,dx\,(1+o(1)), \] whose integral from $0$ to $\varepsilon$ is finite; so the puncture lies at finite distance and the metric on $M$ is incomplete. The distance is not zero: on the annulus $\varepsilon/2\le S_2^{1/2}\le r$ the conformal factor is bounded below by a positive constant, so every path from a point of radius $\varepsilon$ to the puncture has length bounded below. \end{proof} The theorem answers the question the review posed, and it is worth noting what it does \emph{not} do. Its puncture set is not stipulated: by Theorem~\ref{thm:p0-punctures-are-critical}, applied to the extending Euclidean background of this construction, the set $S$ must equal the critical set, and the proof above computes that critical set on $\overline M=D_r$ to be $\{0\}$ alone, so the model's puncture is forced by $a$. What the theorem does not do is attach the configuration to the arithmetic motions rather than to the assignment, or treat more than one puncture. Finally it makes the interface with Paper~I visible rather than implicit: the zero locus of a regular AES is a smooth curve (Lemma~\ref{lem:p0-gradient-nonvanishing}), the complete-splitting theorem of Paper~I forbids branching on a connected complete boundaryless regular space, and here branching occurs exactly at the puncture --- with the metric incomplete, which is one of the ways the theorem's hypotheses can fail. \begin{corollary}[Puncture counts in the conformal-background class] \label{cor:p0-puncture-count} Under all the hypotheses of Theorem~\ref{thm:p0-punctures-are-critical}, $|S|=|\operatorname{Crit}(\widetilde a)|$. Conversely, if a smooth function $\widetilde a$ on an oriented smooth surface $\overline M$ has a finite critical set $S$, then for every smooth background metric $g_0$ the formula \[ g=\frac{|d\widetilde a|_{g_0}^2}{\mu^2+\lambda^2\widetilde a^2}\,g_0 \quad\text{on }\overline M\setminus S \] constructs a punctured AES with precisely that declared puncture set. \end{corollary} \begin{proof} The equality follows from the theorem with its conformal hypothesis. For the converse, the factor is positive off $S$ and the eikonal identity follows by inverting the factor. At each point of $S$ a non-degenerate regular extension would give $0=\mu^2+\lambda^2\widetilde a^2$, which is impossible. This proves essentiality for the constructed metric, not a classification of arbitrary prescribed metrics. \end{proof} \begin{remark}[A construction rather than a classification] \label{rem:p0-multi-puncture} The corollary supplies models from assignments with finitely many critical points. It does not make an arbitrary AES metric extendible and does not identify all punctures with critical points. Section~\ref{sec:p0-compactification} constructs compactified carriers with every positive finite puncture count; the point at infinity in that family is essential because the assignment diverges, so it is not an additional critical point of a smooth extension. \end{remark} \subsection{Tearing across a puncture} \label{subsec:p0-tearing-at-puncture} The tearing of Definition~\ref{def:p0-tearing} is a defect between two add--scale histories. On a punctured space a further question arises: a comparison of two motions may have to be performed around a puncture rather than through it, and one may ask whether the tearing is then measured by an ACS area, by a holonomy of a loop around the puncture, or by neither. The answer proved below is that it is measured by the ACS area in every case, that no canonical holonomy exists in the AES data, and that what the puncture changes is the admissibility of a \emph{comparison on the surface} rather than the value of the tearing. \begin{proposition}[The tearing does not see the puncture] \label{prop:p0-tearing-puncture-independent} Let $\gamma,\delta$ be scale-compatible add--scale histories over a field $K$, with translation coordinates $\xi_\gamma,\xi_\delta$ as in Section~\ref{sec:p0-affine-cocycles}. Then \[ \tau(\gamma,\delta)=\xi_\gamma-\xi_\delta \] depends only on the two words. Consequently $\tau(\gamma,\delta)$ is unchanged by puncturing the space in which the histories are realized, by changing that space, or by choosing a different realization of the same words; and the area formula of Theorem~\ref{thm:torsion-stokes} applies verbatim on a punctured model, with the filling taken in the charge plane rather than on the surface. \end{proposition} \begin{proof} By Proposition~\ref{prop:affine-cocycle-formulas} the target-frame translation $\xi$ is a function of the chronological word alone, and Definition~\ref{def:relative-torsion} defines $\tau$ as the difference of the two $\xi$'s. Nothing in either statement mentions a surface, a metric, or a puncture. The area formula is Theorem~\ref{thm:torsion-stokes}, whose data are the two charge chains. \end{proof} The next statement explains why the charge plane is the canonical place for the comparison, and it has nothing to do with punctures: on a surface the two orders of a rectangle never close up. \begin{proposition}[The surface never closes the comparison] \label{prop:p0-surface-does-not-close} Let $\mathfrak E$ be a regular AES with canonical frame $(X_u,X_v)$, let $p\in M$, and let $h,k>0$ be such that the flows $\Phi_u^h$ and $\Phi_v^k$ of $X_u$ and $X_v$ are defined at $p$ and along both compositions. Then the two chronological compositions end at points whose assignments differ by \begin{equation}\label{eq:p0-surface-comparison-defect} a\bigl(\Phi_v^k\Phi_u^h(p)\bigr)-a\bigl(\Phi_u^h\Phi_v^k(p)\bigr) =\mu h\bigl(e^{\lambda k}-1\bigr)\ne0 , \end{equation} whenever $\mu h\ne0$ and $\lambda k\ne0$. Hence the two flow paths alone bound no region of $M$: closing them requires a further path along which the assignment changes by that amount. Consequently the ACS comparison of Section~\ref{sec:p0-acs-tearing} is not a device for avoiding punctures. It is the canonical comparison for every regular AES, punctured or not, and the puncture changes nothing about it. \end{proposition} \begin{proof} By Theorem~\ref{thm:continuous-affine-flow}, the flows satisfy $\frac{d}{ds}(a\circ\Phi_u^s)=\mu$ and $\frac{d}{ds}(a\circ\Phi_v^s)=\lambda\,(a\circ\Phi_v^s)$; hence $a\circ\Phi_u^h=a+\mu h$ and $a\circ\Phi_v^k=e^{\lambda k}a$. Composing in the two orders, \[ a\circ\Phi_v^k\circ\Phi_u^h=e^{\lambda k}(a+\mu h), \qquad a\circ\Phi_u^h\circ\Phi_v^k=e^{\lambda k}a+\mu h , \] whose difference is $\mu h(e^{\lambda k}-1)$. This is nonzero under the stated hypotheses, so the two endpoints are distinct; two paths that do not share both endpoints bound no region. \end{proof} \begin{proposition}[No canonical holonomy around a puncture] \label{prop:p0-no-puncture-holonomy} Let $\mathfrak E$ be a regular AES. \begin{enumerate} \item The horizontal structure determined by the assignment is the foliation by the level sets of $a$, whose tangent distribution $\ker da$ is integrable; it is therefore flat, and it has no holonomy. \item The AES data determine no further connection on $M$. A connection with curvature requires a choice of splitting beyond $(M,g,a;\mu,\lambda)$; the contact model of Section~\ref{sec:p0-contact} is one such choice, and relative to its added charge projection the curvature form $\omega$ of Proposition~\ref{prop:p0-curvature-form} is canonical. \item Since the assignment is a globally single-valued function on $M$, no loop around a puncture can change the value of $a$: there is no monodromy of the assignment. \end{enumerate} Hence no tearing is measured by a holonomy of a loop around a puncture. The natural holonomy in this theory lives in the contact model, over a loop in the charge plane, where it is the closed horizontal drift $T_{\mathrm{closed}}=e^{-\lambda k}T_{\mathrm{open}}$ of Section~\ref{sec:p0-contact} --- a holonomy of the added structure, not of the puncture. \end{proposition} \begin{proof} (1) The level sets of a smooth function foliate the open set where its differential does not vanish, and by Lemma~\ref{lem:p0-gradient-nonvanishing} that is all of $M$; the tangent distribution of a foliation is integrable by definition. (2) The canonical frame supplies two global directions, but a splitting of the tangent bundle is not part of the data; ยง9 fixes one by declaring the coordinates $(u,v,a)$ and the charge projection. (3) A single-valued function has no monodromy along any loop. \end{proof} \paragraph{What the puncture does change.} It changes which comparisons can be performed \emph{on the surface}. In the model of Theorem~\ref{thm:p0-four-circle-model} the local picture is computed as follows. \begin{proposition}[The zero-set germ and the metric at the puncture] \label{prop:p0-puncture-local-picture} In the model of Theorem~\ref{thm:p0-four-circle-model}, with $0<\varepsilon<\rho$: \begin{enumerate} \item the circle $S_2=\varepsilon^2$ meets the zero locus in exactly eight points, four on the pair of circles tangent to the $x$-axis and four on the pair tangent to the $y$-axis; \item the assignment changes sign at each of them, and the punctured disc is divided into eight sectors, four with $a>0$ and four with $a<0$; the negative sectors are the cusps $|y|