Reading
The mirror deletion, and the geometry every window
shares.
The tower keeps every finite place and deletes the archimedean
window (The Object); what that deletion costs is
measured on Walls. Two more constructions sit
beside it: the mirror deletion, which keeps only the
archimedean window, and the continued-fraction grid, which is
not positional at all. A single vocabulary prices all of them: 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.
The second deletion
Every wall on Walls measures one deletion —
every finite place kept, the archimedean window removed. The mirror
deletion keeps only the archimedean window, and its rung
element is already in every machine: a floating-point number — sign,
exponent, t leading digits — with the precision ladder as the
mirror of the window ladder. Both deletions embed the integers whole,
so both pose one question with the poles swapped: what does a window
compute of arithmetic at finite precision? The fiber geometry inverts
— a finite window's fibers are arithmetic progressions, the dual
window's are sign-definite contiguous intervals; progressions hide
size, intervals hide residue. Reading at lookahead c
means the output window at precision t is a function of the
input window at precision t + c — at the trailing end,
f(n) mod bt from n mod
bt+c.
The two-pole
reading criterion rule
A window reads f at bounded lookahead iff f
is Lipschitz at cell scale in the window's own metric and the
image of each deep input cell fits one output cell. Cell
scale is load-bearing: the readable class contains below-the-top
digit permutations whose pointwise ratios are unbounded; at ball
windows cell scale and pointwise coincide. The fitting clause is where
windows differ, and it follows from the cell family's Lebesgue
number:
| window | metric | cells | fitting |
| trailing, any digit set | b-ultrametric db |
cosets = balls | automatic (strong triangle) |
| leading, non-redundant | log metric |
partition, Lebesgue number 0 | degenerates to alignment |
| leading, redundant | log metric |
overlapping cover | bought by the cover |
At the trailing end readability is Lipschitz, verbatim:
reading at lookahead c is the statement
db(f n, f n′) ≤
bc db(n, n′), the
minimal lookahead exactly max(0, ⌈logb
Lipb(f)⌉) — multiplication is nonexpanding,
free at c = 0, and ⌊n/v⌋ is Lipschitz iff
rad v | rad b: the trailing division gate is a
b-adic Lipschitz fact. No digit set changes this end — a
redundant prefix's completions fill a full coset, cosets are equal
or disjoint — so redundancy is a leading-end-only door. At the
leading end every scaling is a log-metric isometry, so the whole
gate is alignment: non-redundant, ⌊(u/v)n⌋ is
window-local iff rad u | rad b with the denominator
free (long division emits digits MSB-first from bounded remainder
state); redundant digits {−a..a}, 2a + 1 >
b, make the cells an overlapping cover and both radical gates
dissolve — every rational slope reads at bounded delay, within one
digit of the Lebesgue bound. The lookahead unifies as
logb(Lipschitz constant) plus a window margin: 0
at ultrametric windows,
logb(2a/(2a − b + 1)) at
redundant covers, and infinite — a wall — at misaligned
non-redundant reads. Catastrophic cancellation is the criterion's
negative space: subtraction's log-metric blowup at its zero
locus.
Scope. The four regimes verified under the
one statement at stated scopes. Component tiers: the trailing
instance proved, elementary; the coset rigidity a two-line proof;
the numerator criterion a rule (the boundary-preimage method); the
rational-slope delay law a rule at scanned digit sets (2,1), (4,2),
(10,6).
verifiers:
explore_dual_lipschitz.py,
explore_dual_locality.py,
explore_dual_redundant.py
The exchange of
crown and blind spot property
A product's exponent is read from the operand exponents up to 1,
but equality, comparison of nearby values, and the zero-test of a
difference are unreadable at every finite precision: one
deep fiber realizes difference exponents {0..5}, both signs, and
zero. The finite pole's crown capability — the exact zero-test, a
residue is zero or it is not, in every window — is exactly the dual
pole's blind spot, and the dual pole's native reads — size, sign,
order — are exactly what the tower's deletion removes: the two poles
exchange crown capability and blind spot. The redundant purchase
does not close the gap; it pays with it: behind the cover, sign is
non-local at every lookahead, comparison blurs across 3 cells
against the non-redundant window's 1, and the window cannot read its
own exponent. Redundancy is the archimedean deletion performed a
second time, inside the archimedean window — what it buys is
arithmetic, what it spends is the archimedean data itself.
Scope. Property with witnesses at stated
scopes. The redundant order reads (sign, order blur, normalization)
are rules, the order-blur law an iff, at both scanned redundant
systems.
verifiers:
explore_dual_pole.py,
explore_dual_redundant.py
The two-ends
law rule
Base b's trailing digits read exactly the finite places
p | b; its leading digits perfectly hide exactly the
same places — the bias of [n ≡ r (mod p)] on a
deep leading fiber is exactly zero iff p | b, and
otherwise nonzero on every deep fiber, with a derived attained
ceiling. One numeration, two ends: the same primes exactly readable
at one end, exactly invisible at the other. The same radical
condition runs the arithmetic in exchange — trailing multiplication
free, division gated by rad v | rad b; leading
division free, multiplication gated by rad u | rad b —
one condition on opposite parts of the fraction: each end freely
reads the operation whose carry flow points away from it. And where
a price survives, each pole prices in its own metric's arithmetic.
Dividing by v costs the trailing end
maxp ⌈vp(v)/vp(b)⌉
digits — a maximum over places — while multiplying by u costs
the redundant leading end ⌈Σp
vp(u) logb p +
margin⌉ — a sum over places: the product formula surfacing as the
two poles' price sheet.
Scope. The hiding law, the two-ends law, and
the exchange are rules at stated scopes; the pricing is an identity,
measured.
verifiers:
explore_dual_pole.py,
explore_dual_locality.py,
explore_dual_lipschitz.py
The reading lemma
The criterion above 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 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: Lipschitz at cell
scale, pointwise at ball windows. 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 at growing modulus 2t — and readable at no bounded
lookahead.
Scope. Rule at scanned scopes; the two-pole
regimes above 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, emission grows without bound iff
f(y) ∉ ∂: an image on a vertex is interior to
every image interval, the vertex's two sides agree only to its own
depth, and emission freezes at a computable constant forever — where
a rate stall only slows it. A map's permanent walls are exactly
f−1(∂) ∖ ∂, its rationalizing set. Redundant
covers dissolve every wall — a positive Lebesgue number leaves no
map with a modulus of continuity walled. 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 — the first whose cell mesh is not
a function of digit depth. 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, run as controls).
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 print 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
nonnegative words, word-free at quadratic streams; sign-crossing 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 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 ring class number. 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 sight-unseen; 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 designed run-ahead witnesses.
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 stalling pair (x/2, 2φ) 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 same
pair (2x, φ) stalls at 1/3 in the quotient clock and
runs ahead at 4/3 in the tree clock (φ³ = 2 + √5 makes both
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 pattern
Every window here gates its multiplication-like maps by the same
shape: readable at bounded delay iff the map is a unit of the
window's native structure.
| window | native structure | gated map | the gate |
| trailing b-adic | Z[1/b] |
⌊x/v⌋ | rad v | rad b |
| leading, non-redundant | Z[1/b] on the scale circle |
⌊(u/v)x⌋ | rad u | rad b |
| continued fraction | M2(Z) on quotient strings |
(ax + b)/(cx + d) | det = ±1 |
Nonlinear maps sit under a second gate, orthogonal to units — the
wall criterion: x² reads φ at bounded delay (its orbit
ratio is 1) while walling permanently at √2 (its image is a vertex).
Redundancy splits the gates by shape, and the split is verified at
both poles. 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. Each row a rule at its own scopes;
the cross-window generality is a pattern over these windows, not a
proof.
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,
door, and certificate — at the two ends of a numeration, and along
the continued fraction's grid — is that statement's positive or
negative space.