Reading
The geometry every window shares.
A window is a nested grid of cells refining toward a point,
and what it reads at bounded lookahead is what is Lipschitz at cell
scale in its own metric: reading f at lookahead
c means the output cell at depth t is a function of
the input cell at depth t + c. The positional pair
holds the two ends of that story, and the first two deletions: the
tower reads the trailing digits of a base, every finite place
kept and the archimedean place deleted — the first deletion
(Walls) — while floating point reads the
leading digits — the second, the mirror deletion, keeping only
the archimedean place. Their shared criterion and exchanged blind spots
are on The dual pole. Two constructions sit
beside the pair: the continued-fraction grid, which is not
positional at all, and the Zeckendorf window, which counts by
Fibonacci numbers instead of powers
(Completions). A digit set larger than the
base — digits {−a..a} with 2a + 1 >
b — is redundant: its cells overlap instead of
partitioning. Throughout, rad m is the product of m's
distinct primes.
- Completions — the limit object behind the gate, and its shapes
- Quadratic windows — the window every quadratic irrational carries, and its gate
- Digit shifts — moving every digit up by a stride, and which of those moves a bounded reader can follow
- The widened output — ×m read at bounded lookahead once the reader may write past legality, the floors torn regardless, and the two-digit floor that finishing on an integer costs
- Redundant arithmetic — what a redundant digit set makes local, and at what delay
The reading lemma
The two-pole reading criterion
(The dual pole) names a
metric and a cell family and nothing
else — so it generalizes past the positional pair. A window is a
metric measure geometry (X, d, μ,
{Ct}): a metric, a measure, and a nested cover
sequence with mesh δt → 0 and Lebesgue numbers
ℓt. A reader of f at lookahead c maps
each deep input cell — every cell past some level of the
nest — into an output cell containing its image,
refinement-compatibly: the chosen output cells nest as the input
refines, so the output is one committed digit stream.
The reading
lemma rule
If f is Lipschitz with constant L, it fits
cell-to-cell at lookahead c once
L·δt+c <
ℓt — per-level fitting, which is readability
outright where cells nest. Necessity is coarse: a readable map need
only be Lipschitz at cell scale — pointwise Lipschitz follows where
the cells are metric balls, and the leading window has maps readable
at lookahead 0 with unbounded pointwise ratio. Three cover shapes give three
regimes — balls of an ultrametric
(ℓt = δt, fitting automatic,
margin 0); a partition of a connected space
(ℓt = 0, the lemma silent — readability a per-map
alignment question); an overlapping cover with
ℓt = ρδt (fitting bought at
margin logb(1/ρ)). At overlapping covers a
redundant cell's children keep the overlap only in its interior, so
the committed stream departs from the per-level bound by at most one
digit — both directions realized at scanned witnesses; the bound is
exact where cells nest. And readability is metric, not
topological: even-position digit extraction is uniformly continuous
— readable only at a modulus that grows with depth — and readable at
no bounded lookahead.
Scope. Rule at scanned scopes; the two-pole
criterion's regimes are its positional instances.
verifier:
explore_reading_geometry.py
The wall
criterion rule
At partition covers the lemma is silent, and the permanent-wall
half of the alignment question is answered by the cover's vertex
set ∂ — the cell-boundary points, which stay cell endpoints at
every deeper level. For f continuous and strictly monotone at
an irrational input y, the emitted digit count grows without
bound iff f(y) ∉ ∂. Off ∂ the image sits strictly
inside a cell at every depth, and the shrinking image intervals fit
those cells one after another; an image on a vertex instead
straddles it forever — a vertex lies interior to every image
interval, and its two sides agree only to the vertex's own depth —
so emission freezes at a computable constant, where a rate stall
only slows it. A map's permanent walls are exactly
f−1(∂) ∖ ∂, its rationalizing set. Redundant
covers dissolve every wall: with a positive Lebesgue number no
uniformly continuous map walls, an image interval smaller than that
number fitting inside some cell wherever it lands. Wall exposure is therefore
the size of the vertex set, and the continued fraction's — all of
Q — is the largest a rational-vertex grid can have (base
b: Z[1/b] ⊂ Q). The cross-window
witness: x² walls permanently at √(1/3) in the
continued-fraction grid and reads on in base 10.
Scope. Rule at scanned scopes — the maps
x² (walls at every scanned √r) and
√x (wall-free: a rational square root forces a rational
input); the cure realized at every scanned wall of x².
verifiers:
explore_cf_nonlinear.py,
explore_cf_redundant.py
The third deletion: the continued-fraction window
Precision t = the first t partial quotients; the cell
of [a0; a1, …,
at] is a Stern–Brocot interval; cells partition the
irrationals at each depth and nest across depths. This is the first
window here that is not positional, and what it deletes is the
constant ruler — the per-digit scale both positional windows
hold fixed: its cell mesh is not a function of digit depth but of the
number being read. It carries two metrics: the
ultrametric on quotient strings, where reading at lookahead c
is verbatim Lipschitz, and the value metric, where integer Möbius maps
have honest Lipschitz constants. Their exchange rate is the Gauss-map
entropy π²/(6 ln 2) almost everywhere (Shannon–McMillan–Breiman), with
real fluctuations — the all-1s chain (the golden ratio φ) runs
at the floor 2 ln φ, the fattest cells. A positional window is
exactly the zero-variance case, where the two metrics are one ruler —
so bounded lookahead forks here into digit-delay (quotients
consumed minus emitted) and scale-delay (log of precision
consumed over emitted), and the two disagree for real. The window's
own measure is the Gauss measure, and the Gauss–Kuzmin digit law is
this window's mirror of Benford — the invariant measure read through
the digit grid (both classical).
The unit
gate rule
An integer Möbius map with det = ±1 reads continued-fraction
streams at bounded digit-delay: every nonnegative-entry unimodular
map is a positive word in three exact transducers — the Stern–Brocot
factorization — and delays add over a fixed word. A map with
det ≠ ±1 is not boundedly readable: every one owns a mismatched
witness. The sharp witness is 2φ = [3; 4, 4, 4, …] with
φ³ = 2 + √5 exactly, so emitting t quotients of
2φ consumes 3t quotients of φ — delay linear.
Non-unimodularity does not stall every orbit — (2x, √2) reads
at delay zero, since 2√2 keeps √2's rate — it guarantees witnesses
exist. Necessity is proved at quadratic streams: readability
transports through unimodular factors (Smith normal form), reducing
the gate to the scalings x → nx, where φ is a
universal witness — a matched rate would force the multiplier
automorph of nφ to be a power of φ, which floor
rigidity (the period trace is strictly increasing in every digit)
reserves for the all-1s word alone, so nφ's stream would be
φ's own — but the multiplier ring sits inside the lattice,
and φ ∉ Z + Znφ. Serret's theorem —
equal CF tails ⇔
GL(2, Z)-equivalence — is the classical shadow: readable
multiplication is, again, the window's native units.
Scope. Positive direction proved for maps
factoring as nonnegative words, and at quadratic streams outright,
with no word route needed; sign-crossing words at general streams
unscanned. Necessity proved at quadratic streams
from proved pieces (floor rigidity, rate forcing, Serret
transport).
verifiers:
explore_cf_window.py,
explore_cf_conductor.py,
explore_cf_flow.py
The conductor
law rule
At a quadratic stream the rate is arithmetic. The tail's
period-matrix eigenvalue η equals
εi(y)
— ε the field's fundamental unit, i(y) the unit
index of the multiplier order of the lattice
Z + Zy — so the cell-scale rate is
r(y) = 2 i(y) RK /
ℓ(y) (RK the regulator,
ℓ the period length), and a measured stall ratio is
(iout/iin)·(ℓin/ℓout).
The delay is an instrument: the stall slope of x →
nx measures the unit index of a conductor order. Where the
classical index ceiling is not attained, the law follows the
realized index and the deficit is the order's ring class number
against the field's. And the law
is map-blind: any monotone C¹ map with nonzero derivative is
conductor-priced at quadratic orbits — the map enters only through
which output orbit it selects.
Scope. Rule at 17 measured pairs including
four predicted before measurement; the automorph identity
η = εi exact at all 53 scanned pairs (the
eigenvalue identity itself is classical); map-blindness proved at
the flow layer's scope, measured within 1% at all six scanned
nonlinear pairs.
verifiers:
explore_cf_conductor.py,
explore_cf_nonlinear.py,
explore_cf_flow.py
The commitment
bound and rate forcing rule
Every scanned window's digit process is the shift of an expanding
map whose per-digit scale ln |T′| is the roof of a suspension
flow, and the flow's entropy is exactly 1 (Rokhlin's and Abramov's
formulas): entropy per digit equals scale per digit, a positional
window being the constant-roof case. The continued fraction's
suspension is the modular geodesic flow (Artin, Series), where a
quadratic tail rides a closed geodesic of flow period
2 ln η = 2 i RK per tail period —
the conductor rate is the per-orbit return-time mean (the roof
identity: over one tail period the product of complete quotients
equals η, verified exactly at 25 tails). On this flow the
commitment deficit D(n) = scale(image interval)
− scale(committed cell) obeys 0 ≤ D(n) ≤
3 ln(A + 2) + O(1) for monotone C¹ maps at badly approximable
non-vertex outputs (quotients ≤ A): every reader is
scale-synced regardless of the map — the scale clock always
syncs, only the digit clock forks. Rate forcing: at an
eventually periodic tail with quadratic output, emission is
(rin/rout)·n + O(1) with
the ratio rational — digit delay is bounded iff the rates match,
else linear with the mismatch sign, both signs realized. At a wall
the deficit grows linearly instead: measured slope at
(x², √2) is 1.7627 = 2 ln(1 + √2) to four decimals — the cusp
excursion that never returns.
Scope. Both proved at stated scope — the
bound by scale accounting plus bad approximability, the forcing
verified at ten pairs including two witnesses constructed to run
ahead.
The ergodic vocabulary (suspension, roof, Abramov's formula) is
classical import; the reading layer on top is the content.
verifier:
explore_cf_flow.py
The redundant cover
and the ladder law rule
The window's native redundant cover adds to the Stern–Brocot
cells the straddle chains: at a vertex v with Farey
parents (l, r), the chain cell
Sk(v) runs between the k-th mediants
and contains v in its interior at every k. The
alphabet is the exact-real-arithmetic classic — the root straddle is
the image (1/2, 2) of the modified Stern–Brocot digit M (Niqui's
{L, R, M} digit set), and productivity for Möbius maps is classical
(Gosper, Vuillemin, Edalat–Potts); what the overlap does and cannot
do is the content. The ladder law: the cover cells containing
a point z are z's own cell ladder plus a chain segment
of exactly K(v, z) =
⌊1/(qv²|z − v|) −
qfar/qv⌋ rungs at each
approached vertex — at a convergent, K equals the next
partial quotient verbatim; at a rational the chain is infinite. The
cover is graded: rank steps by +1 along every child relation, so
overlap adds routes, never length. The two gates then split.
The wall gate falls: x² reads √2, √3, √(3/2) through
the chain with never-freezing emission, ln k slope equal to
the input's scale rate to four decimals — the emitted stream is an
infinite redundant representation of the rational output, the
continued-fraction mirror of 0.1999… The rate gate stands: at
the scanned pair (x/2, 2φ) — the staller of the
tree clock, delay counted in Stern–Brocot tree steps rather
than in quotients, its emission slope 3/4 — the maximal rank
of a cover cell containing the image equals the plain tree position
at every sampled depth — ladder spacing is orbit data no overlap
changes, so rate forcing survives redundancy verbatim. And a delay's
sign belongs to the clock: the inverse reading
(2x, φ) of the same two streams stalls at 1/3 in the
quotient clock and runs ahead at 4/3 in the tree clock, and
(x/2, 2φ) does the reverse (φ³ = 2 + √5 makes
all four slopes exact) — only the mismatch belongs to the orbit, and
the scale clock is the invariant ruler.
Scope. The ladder law's closed form exact at
every scanned node (510 nodes × 12 depths); the rank grading a
property on every child relation; the wall cure and the rate gate
rules at scanned scopes.
verifier:
explore_cf_redundant.py
The two gates
The two gates
across windows rule
Every window here gates its multiplication-like maps by the
same shape: readable at bounded delay iff the map extends to a
Lipschitz self-map of the window's completion. A window's
completion is the limit object its nested cells define — the
infinite digit strings, with the finite ones dense inside — and it is
not the same object at every window
(Completions). Every row of the
table states that gate instead as unit-ness, and rightly: a
window whose digit string carries a shift action has a native unit
group, and there the two gates coincide. What the rows cannot show is which of the
two is doing the work — the family below answers that, and the answer
is not unit-ness.
| window | native structure | gated map | the
gate |
| trailing b-adic | Z[1/b] |
⌊x/v⌋ | rad v | rad b —
v a unit |
| leading, non-redundant | Z[1/b] on the scale
circle |
⌊(u/v)x⌋ | rad u | rad b —
u a unit |
| continued fraction | M2(Z) on quotient
strings |
(ax + b)/(cx + d) | det = ±1 —
the map in GL(2, Z) |
| trailing Zeckendorf | Z[φ] on digit
strings |
n ↦ mn, n ↦ ⌊n/m⌋ |
m ∈ ±φZ — m a
unit |
| trailing Ostrowski,
α quadratic |
Z[α] on digit strings |
n ↦ mn, n ↦ ⌊n/m⌋ |
m ∈ ±εZ — m a
unit |
Nonlinear maps sit under a second gate, orthogonal to units — the
wall criterion: x² reads φ at bounded delay (its input
and output orbits share a rate) while walling permanently at √2 (its
image is a vertex).
Redundancy splits the gates by shape, and the split is verified at
both redundant covers. The redundant leading window dissolves its gate
wholesale, because positional roofs are constant — scale rates
always match there, so the only gate was boundary alignment, which
any positive Lebesgue number kills. The redundant continued-fraction
cover dissolves only the wall gate — its roofs are orbit-pinned, so
overlap extends terminated ladders (rationals: walls cured) while
never raising the reachable rank at an irrational (rate forcing
survives). One purchase — a positive Lebesgue number — two fates,
decided by whether the window's roof is constant or carries orbit
data.
Scope. The gate's iff is a theorem: delay c is exactly Lipschitz constant 2c
in the agreement ultrametric on digit strings, and a Lipschitz map on a
dense subset of a complete space extends uniquely — what it leaves
between Lipschitz and discontinuous is the class the reading lemma's
even-position extraction inhabits
(Completions). Each row a rule at
its own scopes; the gated half is a theorem at Zeckendorf (×2), and
the last row's own theorem families are stated where they are proved
(Quadratic windows). The redundancy
split is a rule at the two covers scanned.
verifiers:
explore_dual_lipschitz.py,
explore_cf_window.py,
explore_cf_redundant.py
Deletion is the price of locality: a window reads exactly what is
continuous in the geometry its deletion leaves it, and every wall,
gate and cure here — at the two ends of a numeration, and along
the continued fraction's grid — is that statement's positive or
negative space.
What the windows complete to
The gate's native form is an action on
the limit object a window's nested cells define, and that object is not
the same twice. Base b completes to a ring, so every integer
multiplication is continuous there and only division is gated. The
trailing Zeckendorf window — counting by Fibonacci numbers instead of by
powers, its base ratio φ a unit of Z[φ] where an
integer m ≥ 2 is not — completes to a space that is not
a ring: ×2 has no continuous extension on it, a theorem with no range
cap, and every other non-unit tested fails there too. The golden
positional base completes to nothing new at all, its cells being
singletons from the first cutoff up. Above those three stands a shape
none of them describes, at every recurrence degree past the second, and
past those a fifth where the image limit points stop being finitely
many — and wherever it has been read, the arithmetic keeps clear of the
class between Lipschitz and discontinuous —
Completions.
The family above Zeckendorf
Zeckendorf is one window of a family
with a member for every quadratic irrational — the trailing
Ostrowski windows, which count by the convergent denominators
of an irrational α's continued fraction as Zeckendorf counts by
the Fibonacci numbers, φ's own — and across the quadratic
windows tested the gate tracks the unit group of Z[α], so
the whole family completes as Zeckendorf does, to an object that is not
a ring.
That tracking is a fact about these windows and not about the gate: a
quadratic window's continued fraction is eventually periodic, which is
exactly what gives it a unit for the gate to track. The not-a-ring half of that
placement is proved
by an explicit witness family at every constant-a and [0; 1, a]
period-2 window and at period-3 [0; 1, 1, 2], and at every irrational
window, for every multiplier, by a family built on two consecutive
convergents whose images straddle a point the completion codes twice
— the flip's address a theorem everywhere, with a certified boundary family and
one 2-adic criterion on the multiplier deciding where the older
witness runs beside it —
Quadratic windows.
The second deletion
The positional pair carries one criterion
with the poles swapped: a window reads a map at bounded lookahead iff
the map is Lipschitz at cell scale in the window's own metric and
each deep cell's image fits one output cell — the fitting clause
priced by the cell family's Lebesgue number. The two
poles exchange crown and blind spot — the tower's exact zero-test
against floating point's native size, sign and order — and base b's trailing
digits read exactly the primes p | b that its leading
digits perfectly hide —
The dual pole.