Part I
State preparation
Fix a normalized target state, construct a unitary, and prove that its action on the all-zero state gives exactly those amplitudes.
Read the state-preparation route →Formal quantum computing, read alongside Lean
QuantumComputinglib is the textbook and declaration browser for ASPBE. The current book has two primary parts: State Preparation and Block Encoding. State Preparation is the nested preparation layer used by many broader block-encoding constructions; its certificate remains meaningful on its own. A reverse block-to-state use is a separate downstream theorem with additional input, success, normalization and amplification obligations.
Choose the problem first
The main curriculum relation is State Preparation → Block Encoding: PREPARE is a reusable subproblem inside many block-encoding routes. A block-to-state consumer path also exists, but it is not the inclusion relation and it needs extra branch, normalization and amplification hypotheses. Shared foundations are authored once rather than duplicated.
Part I
Fix a normalized target state, construct a unitary, and prove that its action on the all-zero state gives exactly those amplitudes.
Read the state-preparation route →Part II
Fix an operator, normalization, ancilla convention, and register order; then prove that the projected block of a larger unitary has the requested value.
Read the block-encoding route →State-preparation workflow
Normalization, unitarity, and state action are separate obligations. The first-column identity is the matrix form of the same state-action equation.
flowchart LR T["Target state<br/>|ψ⟩"] --> N["Check normalization<br/>⟨ψ|ψ⟩ = 1"] N --> C["Choose a circuit<br/>or unitary completion"] C --> U["Prove U is unitary"] C --> A["Prove the state action<br/>U|0ⁿ⟩ = |ψ⟩"] U --> L["Lean state-preparation<br/>certificate"] A --> L L --> E["Export one certified<br/>finite instance"] classDef target fill:#ffffff,stroke:#6b6045,color:#222222,stroke-width:1.5px; classDef work fill:#ffffff,stroke:#64747a,color:#222222,stroke-width:1.25px; classDef proof fill:#ffffff,stroke:#2f7355,color:#18382b,stroke-width:1.5px; class T,N target; class C,U,A work; class L,E proof;
Block-encoding workflow
This route introduces choices that state preparation does not need: ancilla count, a clean projector, register layout, normalization \(\alpha\), and an exact or approximate block norm.
flowchart LR T["Target operator A<br/>and scale α"] --> R["Fix ancillas, norm,<br/>and register order"] R --> C["Choose a construction<br/>family and unitary U"] C --> U["Prove U is unitary"] C --> B["Prove the clean block<br/>‖A − α Π U Π†‖ ≤ ε"] U --> L["Lean block-encoding<br/>certificate"] B --> L L --> E["Export and check one<br/>certified finite instance"] classDef target fill:#ffffff,stroke:#49677d,color:#1f2e39,stroke-width:1.5px; classDef work fill:#ffffff,stroke:#64747a,color:#222222,stroke-width:1.25px; classDef proof fill:#ffffff,stroke:#2f7355,color:#18382b,stroke-width:1.5px; class T,R target; class C,U,B work; class L,E proof;
Current checkout
Compiled means the Lean and test gates
passed on commit c681192368c2. A contract
record may compile even when a concrete construction route is still partial; the
site shows those two statuses separately.
Shared evidence discipline
ASPBE explores candidates, records why routes fail, and lets Lean decide formal promotion. A Qiskit check is useful finite evidence after certification; it does not prove a symbolic family.
flowchart LR
C["Fixed mathematical<br/>contract"] --> O["Named proof<br/>obligations"]
O --> P["Candidate routes<br/>with provenance"]
P --> L{"Lean gate"}
L -- "proof fails" --> F["Classified failure<br/>and next local lemma"]
F --> P
L -- "certificate compiles" --> X["Finite export<br/>and circuit check"]
X --> D["Documented result<br/>with stated scope"]
classDef contract fill:#f8f5ee,stroke:#826a32,color:#222222,stroke-width:1.5px;
classDef process fill:#ffffff,stroke:#64747a,color:#222222,stroke-width:1.25px;
classDef gate fill:#edf5f1,stroke:#2f7355,color:#18382b,stroke-width:1.5px;
classDef feedback fill:#fff2ef,stroke:#a44b3f,color:#4a2520,stroke-width:1.25px;
class C contract;
class O,P,X,D process;
class L gate;
class F feedback;
Use the project
The public site is not only a declaration catalog. It keeps the original user-facing task builder, the local-compilation workspace, and the reviewed contribution route beside the textbook.
Follow a formula from its physical meaning to the exact Lean declaration.
Open the book map →Edit a theorem, inspect dependencies, and compile temporary code with the local companion.
Open the workspace →Describe a target state or operator, choose a harness, and export a reproducible task packet.
Open the task builder →Project record
The dates below are repository milestones. They do not replace the generated proof-status pages.
QuantumComputinglib now freezes source-facing quantum contracts before proof search, types and salvages failed routes before cleanup, keeps environment/API failures separate from mathematical refutation, defaults routine coordination to deterministic/low-token control in light of local route-ablation evidence, requires distinct uncertainty for parallel Workers, and seals PURIFIED reader explanations against the source and Lean graphs.
The smooth auxiliary \(p\)-register state required by Jin–Liu–Ma’s PDE Schrödingerisation construction, viewed alongside the smooth-function state-preparation route of Holmes–Matsuura, has exact Hermite–Bernstein/tensor-train structure. ASPBE turns generic \(\Theta(2^{n_p})\) amplitude loading into \(G\le48n_p(2k+6)^3\), hence \(O(n_p)\) gates for fixed \(k\), with \(O(\log k)\) workspace. Open the Lean-verified worked case →
For the selected \(n=3\) Robin boundary instance in Guseynov–Huang–Liu, Block encoding by signal processing, ASPBE reduced the audited \(T^{\dagger 3}\) branch from 49 to 30 \(T^{\dagger 3}\) gates and from 52 to 32 CNOTs, with the same five qubits and zero ancillas under the fixed primitive model.
The two application tracks, local workspace, task builder, and contributor review path are presented in one site.
One generated inventory now drives the checked Blueprint catalog and searchable declaration browser.
The site exposed separate State Preparation and Block Encoding directions and the user task builder.
The initial commit and timestamped manifest begin the public, auditable project history. No earlier date is asserted without evidence.
Reading guide
Chapters 1–2 are shared foundations authored once and reused by Block Encoding; Chapters 3–4 specialize them to preparation certificates.
Block Encoding reuses the same finite-matrix and circuit nodes, then adds projected-block, composition, resource and proof-gated construction obligations.