Samplinglib
Lean gate passed 2026-08-19T06:32:39.895922+00:00 · 7bcd37294df1
Registry leaf card · ito-integral.progressive-l2-truncation

tendsto_clipped_toLp

compiled Samplinglib leaf Not mapped explicit smoke test

- Bounded progressive truncations converge to the original integrand in the actual product-space `Lp` object.

Plain-English statement

- Bounded progressive truncations converge to the original integrand in the actual product-space `Lp` object.

Scope guard. This card records a compiled local declaration. Its mathematical scope is exactly the Lean statement below; the Registry note and source correspondence may describe motivation but do not strengthen it.
Lean learning studio · mathematics → formal proof

Read the mathematics first, then descend into Lean

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BeginnerWhy this theorem exists → intuition → statement → one hand calculation. Hide proof-engineering detail.
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Proof architecture

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How to read the exact Lean declaration

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  1. NameWhat reusable mathematical fact is being created?
  2. ParametersWhich symbols are arbitrary, and which structures are inferred by typeclass search?
  3. PropositionAfter the colon, translate the Lean expression back into a paper statement.
  4. Proof actionsAfter by, ask what each tactic does to the mathematical goal—not only what syntax it uses.

Syntax used on this page

This glossary is filtered to syntax that actually occurs in the declaration above. Open a symbol only when you meet it, rather than memorizing Lean grammar in advance.

Source voice and ASTIS voice stay separate

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Lean statement

theorem tendsto_clipped_toLp
    (eta : ProgressiveL2Integrand filtration mu T) :
    Tendsto (fun n => (clipped eta n).toLp) atTop (𝓝 eta.toLp) := by
  simpa [ProgressiveL2Integrand.toLp, clipped, processFunction_clipProcess] using
    (tendsto_clipNat_toLp eta.memLp)

end ProgressiveL2Truncation
end StochasticProcesses
end TechnicalLemmas
end AutoSamplingTheory

Proof architecture

reduce a progressive square-integrable process to uniformly bounded progressive processes in product-space L2

Lean proof walkthrough

  • Read the quantified variables and typeclass brackets as part of the mathematical statement; inferred arguments are not missing assumptions.
  • `simpa` closes the goal after a controlled simplification of a typed result.

Why the statement has this shape

The declaration is kept at the reusable level recorded by its Registry tags and direct consumers. Explicit measures, spaces, wrappers, and regularity hypotheses expose interfaces that paper notation often infers. A theorem card explains those interfaces but never widens the compiled statement.

Hidden assumptions and non-claims

  • Measurability is represented explicitly or must be supplied by a dependency.
  • Integrability is an input or proved output; a displayed integral alone does not supply it.
  • Density statements retain normalization and absolute-continuity prerequisites.
Common pitfall. A wrapper or display identity is not a new analytic theorem merely because it has its own Lean name. Check the statement, hypotheses, and downstream consumers before interpreting its mathematical contribution.