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Transport and realization

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10 Coordinate transport, morphisms, invariant exact sequences, and completion

Reader roadmap

This section follows packet data through changes of coordinates, maps between systems, and passage to a quotient. It then explains the additional assumptions needed when density, topology, or completion enters the argument.

10.1 Coordinate changes and packet compatible morphisms

Theorem 10.1: Coordinate transport

Let \(U:X\to Y\) be a vector space isomorphism and let \({\mathcal P}=(P_\alpha)\) be a packet system on \(X\). Define

\[ Q_\alpha:=UP_\alpha U^{-1}. \]

Then \({\mathcal Q}=(Q_\alpha)\) is a packet system on \(Y\). For \(\widetilde T=UTU^{-1}\),

\[ \boxed{ Q_\beta\widetilde TQ_\alpha = U(P_\beta TP_\alpha)U^{-1}. } \]

Hence packet dimensions, zero patterns, and support preorders are invariant under coordinate transport. If a declared algebra generating family \(\mathcal G\) is transported to \(U\mathcal G U^{-1}\), then its transfer graph and reachability relation are also preserved.

Proof of Theorem 10.1

Conjugation preserves products and sums, so

\[ Q_\alpha Q_\beta =UP_\alpha P_\beta U^{-1} =\delta_{\alpha\beta}Q_\alpha, \qquad \sum_\alpha Q_\alpha=I_Y. \]

The block identity is direct multiplication:

\[ Q_\beta\widetilde TQ_\alpha =UP_\beta TP_\alpha U^{-1}. \]

All listed invariants are determined by these transported blocks.

How to read the result

An isomorphism changes the coordinates of each packet while preserving the direct sum structure. Conjugating the projectors and the operator together preserves every block identity. This is the linear prototype for the gauge changes used later in the series.

Definition 10.2: Packet compatible operator morphism

Let \((X,{\mathcal A},{\mathcal P})\) and \((Y,{\mathcal B},{\mathcal Q})\) be packet resolved operator modules with packet index sets \(I\) and \(J\). A packet compatible operator morphism is a triple

\[ (\Phi,\varphi,\sigma) \]

consisting of a unital algebra homomorphism \(\varphi:{\mathcal A}\to{\mathcal B}\), a linear map \(\Phi:X\to Y\) satisfying

\[ \Phi(Ax)=\varphi(A)\Phi(x), \]

and a map \(\sigma:I\to J\) satisfying

\[ Q_j\Phi = \Phi P_{\sigma^{-1}(j)}, \qquad P_{\sigma^{-1}(j)}:= \sum_{\sigma(\alpha)=j}P_\alpha. \]

An empty fiber is interpreted as the zero projector.

The packet index map records which source packets are grouped into each target packet. Its compatibility equation says that projecting after transport gives the same result as first collecting those source packets. The intertwining equation separately ensures that the declared operator actions agree with the transport. Both conditions matter when comparing transfer blocks.

Definition 10.3: Morphism of seeded systems

A morphism

\[ (X,{\mathcal A},S,{\mathcal P})\longrightarrow(Y,{\mathcal B},S',{\mathcal Q}) \]

is a packet compatible operator morphism satisfying the seed condition

\[ \Phi(S)\subseteq{\operatorname{Hull}}_{{\mathcal B}}(S'). \]

In the topological category all maps and actions are required to be continuous and the seed condition uses the topological hull when declared.

Theorem 10.4: Naturality of generated hulls and transfer blocks

Let \((\Phi,\varphi,\sigma)\) be a packet compatible operator morphism. For every subset \(S\subseteq X\),

\[ \boxed{ \Phi({\operatorname{Hull}}_{{\mathcal A}}(S)) = {\operatorname{Hull}}_{\varphi({\mathcal A})}(\Phi(S)) \subseteq {\operatorname{Hull}}_{{\mathcal B}}(\Phi(S)). } \]

For \(T\in{\mathcal A}\) and \(i,j\in J\),

\[ \boxed{ Q_j\varphi(T)Q_i\Phi = \sum_{\substack{\sigma(\beta)=j\\\sigma(\alpha)=i}} \Phi P_\beta TP_\alpha. } \]

If \(\Phi\) is surjective and \(S\) generates \(X\), then \(\Phi(S)\) generates \(Y\) under \(\varphi({\mathcal A})\) and hence under \({\mathcal B}\). If, in addition, the morphism is seeded, then \(S'\) generates \(Y\).

Proof of Theorem 10.4

Every element of \(\Phi({\operatorname{Hull}}_{{\mathcal A}}(S))\) is a finite sum of vectors

\[ \Phi(As)=\varphi(A)\Phi(s), \]

so it belongs to \({\operatorname{Hull}}_{\varphi({\mathcal A})}(\Phi(S))\). Conversely, every generator \(\varphi(A)\Phi(s)\) equals \(\Phi(As)\), giving equality.

For the block formula, use intertwining and packet compatibility twice:

\[\begin{aligned} Q_j\varphi(T)Q_i\Phi &=Q_j\varphi(T)\Phi P_{\sigma^{-1}(i)}\\ &=Q_j\Phi TP_{\sigma^{-1}(i)}\\ &=\Phi P_{\sigma^{-1}(j)}TP_{\sigma^{-1}(i)}\\ &=\sum_{\substack{\sigma(\beta)=j\\\sigma(\alpha)=i}} \Phi P_\beta TP_\alpha. \end{aligned}\]

If \(\Phi\) is surjective and \({\operatorname{Hull}}_{{\mathcal A}}(S)=X\), the hull equality gives \(Y={\operatorname{Hull}}_{\varphi({\mathcal A})}(\Phi(S))\). If \(\Phi(S)\subseteq{\operatorname{Hull}}_{{\mathcal B}}(S')\), then \({\operatorname{Hull}}_{{\mathcal B}}(\Phi(S))\subseteq{\operatorname{Hull}}_{{\mathcal B}}(S')\), so \(S'\) generates \(Y\).

The central idea

Naturality gives two ways to compute the same transported block. One may apply the target operator between target projectors, or sum the source blocks whose packet indices map to those target indices and then apply the morphism. The theorem also identifies the image of the generated hull. These equalities make the comparison between the two systems precise.

Proposition 10.5: Category of seeded packet systems

Packet compatible operator morphisms compose, seeded morphisms compose, and identity morphisms satisfy both definitions. Thus packet resolved operator modules form a category \(\mathbf{PktMod}\) and seeded packet systems form a category \(\mathbf{SeedSys}\).

Proof of Proposition 10.5

Let \((\Phi,\varphi,\sigma):(X,{\mathcal A},{\mathcal P})\to(Y,{\mathcal B},{\mathcal Q})\) and \((\Psi,\psi,\tau):(Y,{\mathcal B},{\mathcal Q})\to(Z,{\mathcal C},{\mathcal R})\) be morphisms. Intertwining is preserved because

\[ \Psi\Phi(Ax) = \Psi(\varphi(A)\Phi x) = (\psi\circ\varphi)(A)\Psi\Phi x. \]

For \(k\) in the target packet set,

\[\begin{aligned} R_k\Psi\Phi &=\Psi Q_{\tau^{-1}(k)}\Phi\\ &=\Psi\Phi \sum_{\tau(\sigma(\alpha))=k}P_\alpha. \end{aligned}\]

Thus the composite packet map is \(\tau\circ\sigma\). If the morphisms are seeded, then

\[ \Phi(S)\subseteq{\operatorname{Hull}}_{{\mathcal B}}(S'), \qquad \Psi(S')\subseteq{\operatorname{Hull}}_{{\mathcal C}}(S''). \]

By Theorem 10.4,

\[ \Psi\Phi(S) \subseteq \Psi({\operatorname{Hull}}_{{\mathcal B}}(S')) \subseteq {\operatorname{Hull}}_{{\mathcal C}}(\Psi(S')) \subseteq {\operatorname{Hull}}_{{\mathcal C}}(S''). \]

Identity maps satisfy the definitions with identity algebra and packet maps.

10.2 Invariant subspaces and quotient packets

Passage to a quotient uses two separate invariance assumptions. The packet projectors must preserve the subspace for packet coordinates to descend. An operator must also preserve that subspace for its action, and hence its transfer blocks, to descend. The first condition is enough for the packet exact sequence. The second enters the corollary about transfer blocks.

Theorem 10.6: Packet exact sequence for an invariant subspace

Let \(K\leq X\) satisfy \(P_\alpha K\subseteq K\) for every \(\alpha\). Define

\[ K_\alpha:=P_\alpha K=K\cap X_\alpha \]

and

\[ \overline P_\alpha(x+K):=P_\alpha x+K. \]

Then:

  1. The nonzero restrictions \(P_\alpha|_K\) form a packet system on \(K\).

  2. The nonzero \(\overline P_\alpha\) form a packet system on \(X/K\).

  3. For every \(\alpha\) there is a short exact sequence

    \[ 0\longrightarrow K_\alpha \longrightarrow X_\alpha \longrightarrow \overline P_\alpha(X/K) \longrightarrow0, \]

    and

    \[ \overline P_\alpha(X/K) \cong X_\alpha/(X_\alpha\cap K) \cong (X_\alpha+K)/K. \]
  4. The full exact sequence decomposes packetwise as the direct sum of these short exact sequences.

Proof of Theorem 10.6

Restriction preserves idempotency, pairwise annihilation, and the identity sum on \(K\). If \(x\in K\cap X_\alpha\), then \(x=P_\alpha x\in P_\alpha K\), proving \(K_\alpha=K\cap X_\alpha\).

The quotient operator is well defined because replacing \(x\) by \(x+k\) changes \(P_\alpha x\) by \(P_\alpha k\in K\). The idempotent and annihilation identities descend, and the sum is the identity on \(X/K\). The map \(X_\alpha\to X/K\) has image \((X_\alpha+K)/K\) and kernel \(X_\alpha\cap K\), giving the short exact sequence and the quotient isomorphisms. Exact packet coordinates identify the original sequence with the direct sum over \(\alpha\).

Packet descent to a quotient

Let \(X=X_1\oplus X_2\) and let \(K\subseteq X_1\) be a subspace. The quotient has packets \(X_1/K\) and \(X_2\). Any operator preserving \(K\) descends with the same organization by source and target packets, with blocks entering or leaving the first packet replaced by their induced quotient maps. An induced block can become zero even when its original block is nonzero, so the pattern of nonzero blocks can shrink. Any resulting zero packet is removed from the quotient packet system.

Theorem 10.7: Packet descent through an invariant quotient

Under the hypotheses of Theorem 10.6, the operators

\[ \overline P_\alpha(x+K)=P_\alpha x+K \]

are well defined pairwise annihilating idempotents with sum \(I_{X/K}\), and the quotient map satisfies

\[ \boxed{\pi P_\alpha=\overline P_\alpha\pi.} \]

After zero packets are removed, they form the canonical quotient packet system.

Proof of Theorem 10.7

All assertions are the quotient part of Theorem 10.6. The intertwining identity follows directly from the definition:

\[ \overline P_\alpha\pi(x)=P_\alpha x+K=\pi P_\alpha(x). \]

Corollary 10.8: Restriction and quotient of transfer blocks

Under the hypotheses of Theorem 10.6, let \(T\in{\operatorname{End}}(X)\) preserve \(K\). Then every block \(T_{\beta\alpha}\) maps \(K_\alpha\) into \(K_\beta\), and the induced quotient operator \(\overline T\) satisfies

\[ \boxed{ \overline T_{\beta\alpha}\,\pi = \pi T_{\beta\alpha}, } \]

where \(\pi:X\twoheadrightarrow X/K\).

Proof of Corollary 10.8

If \(x\in K_\alpha\), then \(Tx\in K\), so

\[ T_{\beta\alpha}x=P_\beta Tx\in K\cap X_\beta=K_\beta. \]

On the quotient,

\[ \overline T_{\beta\alpha}\pi = \overline P_\beta\overline T\overline P_\alpha\pi = \pi P_\beta TP_\alpha. \]

Corollary 10.9: Topological packet exact sequence

If \(X\) is Banach, the \(P_\alpha\) are bounded, and \(K\) is closed and packet invariant, then every packet sequence in Theorem 10.6 is a short exact sequence of Banach spaces with bounded maps, and the quotient projectors are bounded.

Proof of Corollary 10.9

Closedness of \(K\) makes \(X/K\) Banach. The restricted projectors are bounded, and the quotient projectors are bounded because

\[ \|\overline P_\alpha(x+K)\|_{X/K} \leq \|P_\alpha\|\,\|x+K\|_{X/K}. \]

The packet spaces are closed ranges of bounded idempotents.

10.3 Dense images, quotient topology, and completion

Algebraic generation uses finite linear combinations of operator images. Topological generation allows limits of those combinations in the declared topology. A continuous surjection carries this approximation property to the target, but identifying the target with a topological quotient requires a further assumption.

Theorem 10.10: Dense realization theorem

Let \(X\) and \(Y\) be Hausdorff topological vector spaces, let \(\Phi:X\to Y\) be continuous, surjective, and intertwining with respect to \(\varphi\), and let \(S\) topologically generate \(X\). Then \(\Phi(S)\) topologically generates \(Y\). If finite continuous packet systems satisfy

\[ Q_j\Phi=\Phi P_{\sigma^{-1}(j)}, \]

then

\[ \boxed{ Q_jY=\Phi(P_{\sigma^{-1}(j)}X) } \]

for every \(j\).

Proof of Theorem 10.10

Given \(y=\Phi(x)\), choose a net \(x_\lambda\in{\operatorname{Hull}}_{{\mathcal A}}(S)\) converging to \(x\). Then

\[ \Phi(x_\lambda)\to y, \]

and naturality places every \(\Phi(x_\lambda)\) in \({\operatorname{Hull}}_{{\mathcal B}}(\Phi(S))\). Hence the latter hull is dense. For packets, one inclusion follows from compatibility. Conversely, if \(y=Q_jy\), choose \(x\) with \(\Phi(x)=y\). Then

\[ y=Q_j\Phi(x)=\Phi P_{\sigma^{-1}(j)}x. \]

Theorem 10.11: Quotient topology and completed realization

Let \(\Phi:X\twoheadrightarrow Y\) be a continuous linear quotient map between Hausdorff topological vector spaces, and put \(K={\operatorname{Ker}}\Phi\). Then the induced map

\[ \widetilde\Phi:X/K\longrightarrow Y \]

is a topological isomorphism. If \(D\subseteq X\) is a linear subspace whose image \(\Phi(D)\) is dense in a complete space \(Y\), then the completion of

\[ D/(D\cap K) \]

in the topology transported from \(Y\) is canonically isomorphic to \(Y\).

Proof of Theorem 10.11

The algebraic first isomorphism theorem gives a bijection \(\widetilde\Phi\). By definition of the quotient topology, a set \(U\subseteq X/K\) is open exactly when its preimage in \(X\) is open. Because \(\Phi\) is a quotient map, this is equivalent to \(\widetilde\Phi(U)\) being open in \(Y\). Thus \(\widetilde\Phi\) is a homeomorphism. The second statement applies the dense completion argument of Theorem 3.6 to the injective map \(D/(D\cap K)\to Y\).

Boundary 10.12: Continuous surjections and quotient topology

Continuity and surjectivity transport density as in Theorem 10.10. They do not by themselves identify the given topology on \(Y\) with the quotient topology from \(X\). The stronger conclusion in Theorem 10.11 requires the quotient map hypothesis or an equivalent open mapping condition.

Do not conflate

A continuous surjective linear map need not be a quotient map in arbitrary topological vector spaces. The algebraic first isomorphism theorem gives a bijection on the quotient. A topological isomorphism requires the quotient topology to agree with the target topology. An applicable open mapping theorem can supply this agreement, as it does for continuous linear surjections between Banach spaces.

The completion statement uses the topology transported from the target space. This choice ensures that approximation in the quotient means approximation in the target. A topology inherited from the original subspace need not give the same completion unless the two topologies agree. The theorem therefore names the topology as part of its conclusion.

Section recap

Packet systems transport by conjugation, form a category under packet compatible seeded morphisms, restrict to invariant subspaces, descend to invariant quotients, and survive completion under explicit boundedness and quotient topology hypotheses.

Heatmap of products of transported projectors. Diagonal norms are 12.16, 16.02 and 17.31; off-diagonal norms are about ten to the minus fourteen from roundoff.
Numerical certificate for a nonorthogonal transported packet system. The diagonal products retain idempotent size while off diagonal products remain at roundoff level.

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11 Realization functors and semantic theorem transport

Reader roadmap

A later domain is a genuine realization only when the relevant structures and identities are preserved. The purpose of this section is to replace informal analogy by a precise preservation profile.

11.1 Preservation profiles

Definition 11.1: Realization functor and preservation profile

Let \(\mathbf{SeedSys}_{\mathrm{abs}}\) be an abstract category of seed systems and let \(\mathbf C_D\) be a domain category. A realization functor is a functor

\[ \mathsf{Ev}_D:\mathbf{SeedSys}_{\mathrm{abs}}\longrightarrow\mathbf C_D \]

with a declared preservation profile specifying which of the following structures are preserved:

\[ \begin{gathered} 0,\ I,\ \text{finite sums},\ \text{composition},\ \text{biproducts},\\ \text{kernels},\ \text{cokernels},\ \text{quotients},\ \text{tensor products},\\ \text{packet idempotents},\ \text{transfer blocks},\ \text{topological completions}. \end{gathered} \]

Preservation of a structure means preservation of its defining identity or universal property, not merely a similarity of notation.

Theorem 11.2: Equational realization principle

Let \(F:\mathbf C\to\mathbf D\) be an additive functor between preadditive categories. Any equality of morphisms constructed from declared generating morphisms by finite sums, additive inverses, identities, zero maps, and composition is preserved by \(F\). Scalar multiplication by a coefficient ring is also preserved when the categories are enriched over that ring and \(F\) is linear for the declared enrichment. If a proof additionally uses a chosen biproduct, kernel, cokernel, quotient, tensor product, or completion and \(F\) preserves that construction in its declared profile, then the corresponding proof diagram is transported to \(\mathbf D\).

Proof of Theorem 11.2

Functoriality gives

\[ F(I)=I, \qquad F(g\circ f)=F(g)\circ F(f), \]

and additivity gives

\[ F(0)=0, \qquad F(f+g)=F(f)+F(g), \qquad F(-f)=-F(f). \]

If the declared enrichment is present, linearity additionally gives \(F(af)=aF(f)\) for every coefficient \(a\). A structural induction on the construction of a morphism expression therefore carries every permitted equational proof to its image under \(F\). If a step invokes a universal construction, preservation means that the image diagram satisfies the same universal property. The uniquely induced morphism in the source proof is therefore carried to the uniquely induced morphism in the target proof. Repeating this argument through the finite proof diagram transports the conclusion.

How to read the result

The equational principle covers identities built from operations the functor preserves. Additive identities require additivity. Identities with scalar coefficients require linear enrichment. Quotients, tensor products, completions, kernels, or limits require their own preservation assumptions. The preservation profile records the assumptions needed to carry each step of the proof into the target category.

11.2 From equation transport to semantic realization

Proposition 11.3: Realization export principle

Every canonical Paper I identity whose proof uses only the operations listed in a realization functor's verified preservation profile remains valid after applying that functor. If the proof uses a domain specific hypothesis not encoded by the functor, that hypothesis must be verified separately before the transported statement is promoted to a theorem.

Proof of Proposition 11.3

The first assertion is Theorem 11.2. The second is a logical boundary: a functor transports established identities and preserved universal constructions, but it does not create an unverified analytic, topological, positivity, finiteness, or integrality hypothesis.

Definition 11.4: Semantic realization criterion

A domain theorem is a semantic realization of a canonical seed calculus theorem only when:

  1. An explicit realization functor or intertwining construction is given.

  2. The preservation profile covers every construction used in the canonical proof.

  3. Every additional analytic, finiteness, convergence, positivity, or integrality hypothesis is verified in the domain.

  4. The resulting conclusion is stated in the domain's native objects.

Reuse of the words “seed”, “packet”, or “transfer” without these data is only syntactic reuse.

Do not conflate

A change of nouns is not a realization theorem. Calling a frequency band, a ramification sector, and a symmetry sector a “packet” is only terminology until one exhibits the idempotents, proves reconstruction, identifies the transfer blocks, and checks that the relevant morphisms or limits preserve those structures.

Section recap

The preservation profile determines which equations and proof constructions pass to a new domain. Checking it gives later papers a concrete test for transporting a theorem: identify the realization, check each operation used in the proof, and verify the additional domain hypotheses.

12 Canonical export interface and claim boundary

Reader roadmap

The export interface lets later papers use the foundational proofs directly. Each paper can cite the stable record ID, state its domain hypotheses, and prove the new step specific to its realization.

Definition 12.1: Worked realization interface

The foundational calculus is illustrated by four canonical algebraic realizations:

  1. A typed quiver reachability model.

  2. An algebraic coordinate ring presentation.

  3. A companion and repeated primary single operator model.

  4. Path and cycle adjacency models.

The worked model sections below instantiate these four interfaces. A bilateral shift example records the analytic completion mechanism also used in Paper V. Computational specifications connect the proofs with the verification companion and are not premises of the foundational theorems.

Definition 12.2: Paper I export object

The canonical Paper I export is

\[ \boxed{ \mathsf{PSC}_I= \left( \begin{array}{c} \text{typed grammars and realized operator algebras},\\ \text{seed systems, free presentations, and seed rank},\\ \text{module-top, semisimple, and single-operator formulas},\\ \text{finite and unconditional packet coordinates},\\ \text{transfer blocks and support algebras},\\ \text{reachability and packet-pure source generation},\\ \text{morphisms, invariant exact sequences, quotients, completions},\\ \text{realization functors and equational theorem transport} \end{array} \right). } \]

12.1 Use across papers

Paper I exports and later uses
Paper I exportPrimary usersLater role
Typed grammar and module equivalenceII to XIIGives each domain a legal operator syntax and a concrete module realization.
Free seed presentationIV, IX, XConverts generated families into quotient presentations and relation modules.
Jacobson top seed rankVII, X, XIIComputes minimal generators from semisimple multiplicity data.
Single operator formulaIV, VI, IXResolves recurrence, companion, and spectral chain generator counts.
Exact packet coordinatesII to XIISupplies analysis, synthesis, and packetwise equality.
Tensor and dual packet systemsV, VII, VIII, XIControls product systems, observables, and paired representations.
Transfer block multiplicationII to XIIConverts operator composition into sums over packet paths.
Block intertwining equationsIII, VII, XIExpresses global equivalence or gluing as local packet equations.
Support preorder algebraII, VIII, XProduces triangular transfer structure and nilpotent strict transfer ideals.
Source component seed rankVIII, XIdentifies the packet pure source requirements under propagation hypotheses.
Packet exact sequences and quotient descentIII, VI, X, XIICarries packets through constraints, reductions, and deformation quotients.
Semantic realization criterionIV to XIISpecifies when a domain theorem is a true realization of the common calculus.

Boundary 12.3: Exact limits of Paper I

The existence of an exact packet decomposition does not imply that the decomposition is computationally discoverable, numerically well conditioned, statistically identifiable, dynamically invariant, or mathematically useful. The condition number in Definition 7.11 quantifies only coordinate stability once the packets are supplied. Refinement towers, filtered transfer, nonlinear obstruction objects, automatic packet recovery, continuum limits, arithmetic lifts, and automorphic occupancy require additional theorems in later papers.

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