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 Y-junction satisfies Kirchhoff flux balance
Example
Take three unit edges oriented from a central vertex to leaves , with unit diffusivity and prescribed leaf values , , and . Define on the three edge coordinates , , and for . The common central trace is , and the total outward diffusive flux at is zero.
The arrows give the coordinate orientations from the central vertex; the drawing is schematic and the proof uses the exact endpoint values below.
\begin{center} \begin{tikzpicture}[>=stealth, every node/.style={font=\small}] \node[circle,draw] (v) at (0,0) {}; \node[circle,draw] (a) at (-2,1.4) {}; \node[circle,draw] (b) at (2,1.4) {}; \node[circle,draw] (c) at (0,-2) {}; \draw[->] (v) -- node[above left] {} (a); \draw[->] (v) -- node[above right] {} (b); \draw[->] (v) -- node[right] {} (c); \end{tikzpicture} \end{center}
Facts & Assumptions
Given: The three unit intervals with a common central endpoint, their orientation from to the leaves, unit diffusivity, the displayed edge functions, and zero interior load.
A metric graph has edgewise interval coordinates and common endpoint traces at each vertex (Anchored finite metric graph and its H1 energy space).
For edgewise H2 functions, the signed endpoint terms in Green's identity group by common vertex trace and outward flux; zero test traces remove Dirichlet endpoints (Green identity and Kirchhoff flux cancellation on a metric graph).
The general endpoint-representative interface assumes the Axiom of Choice (The Axiom of Choice, One-dimensional functions have unique absolutely continuous representatives).
Verification
Given: The oriented unit Y-graph and the three edge functions in the Example.
At the central endpoint , all three values equal . At the leaves , the values are , respectively. Hence the functions define a continuous metric-graph function with the specified Dirichlet data.
The outward derivative at the tail is . The three values are , whose sum is . Each edge has . Therefore the edge equation has zero load and the free central vertex satisfies Kirchhoff balance.
For any test function with zero trace at the three leaves, [F2] shows that the edge bilinear form has only the central boundary contribution, which is its test trace times the sum . Thus the displayed function is also a weak harmonic field for these Dirichlet data.
Depends on
Used by
Nothing in the library uses this result yet.
Dependency tree · two levels
30 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.
Sources
- Mario Arioli and Michele Benzi, A Finite Element Method for Quantum Graphs, Emory CS Technical Report TR-2015-009 (44-page full text) (standard reference, not scraped)
- Peter Kuchment, Quantum graphs: an introduction and a brief survey, arXiv:0802.3442 (2008) (standard reference, not scraped)