How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
A nonuniform insulated temperature profile relaxes to its mean
An exact initial-profile example inside the constant-capacity, constant-conductivity insulated rectangular model; it is a conditional calculation, not an observation.
Statement
Assume Countable Choice as in Constant-conductivity heat evolution on an insulated rectangle. Let be lengths in metres and . Let be a constant volumetric heat capacity in , a constant scalar conductivity in , and an arbitrary reference energy density in , with as in Constant-conductivity heat evolution on an insulated rectangle. Let and be temperatures in kelvins with . For set and prescribe Use its even -periodic extension in each coordinate as the initial datum on . The unique insulated heat solution has constant spatial mean and satisfies This gives an exactly computed initial variance and the conditional relaxation estimate of the model.
Facts & Assumptions
Given: Countable Choice; lengths in metres; with the units and hypotheses in the Statement; the profile ; and the field .
Countable Choice is the explicit hypothesis used by the heat-evolution supplier The Axiom of Countable Choice ().
Constant-conductivity heat evolution on an insulated rectangle: the even-periodic compatible initial field has the unique Gaussian-convolution heat solution with positive bounds and homogeneous Neumann faces.
Exponential relaxation of the constant-conductivity Neumann heat model: for this solution, the mean is conserved and .
Example
The function is dimensionless, and has units of kelvins. The extension uses even reflection at each face and period ; the initial field is nonconstant but compatible with insulated walls.
Verification
Write . Then , so , and . Also on . The constant and first two derivatives therefore match across the even-reflection and periodic seams; the extension is , with bounded uniformly continuous derivatives. Since , its values lie in , so .
Expand , so . Also , whence Therefore and Integrating over the other two coordinates now gives and .
The profile satisfies every initial-data hypothesis of [F1]; its vanishing normal derivative follows from . Apply [F1] for existence and [F2] with the computed to obtain the stated conserved mean and decay bound. This is a deduction within the adopted continuum model.