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.
Good copy extension count
Statement
Let have vertices and let be a -blowup in a finite graph , with integer . Every good embedding of , , has at least good extensions to .
Facts & Assumptions
Given: A -blowup of a nonempty -vertex pattern, integer , , and a good partial embedding .
In a -blowup, every vertex of either block has at most wrong adjacencies in the other block; good embeddings respect the assigned labels. (Labelled blowup and good induced copy).
Proof
Induct on . When , the given map is its unique extension and the bound is .
Let and assume the assertion for . Choose a missing label . For every , [F1] bounds by the vertices in with the wrong adjacency to . The union of these forbidden sets has size at most : assign each forbidden vertex to its first offending label, obtaining disjoint subsets of the forbidden sets. Thus at least vertices are available.
Each available gives an induced extension by : the old map already preserves all old pairs, the new pairs have the prescribed adjacency, and disjoint blocks prevent collisions. By induction each such map has at least full extensions. The families for distinct are disjoint since they differ at ; adding their cardinalities gives at least . This proves the induction, including the empty initial map.
Source notes
Proof/convention locator: Bucic, Nguyen, Scott and Seymour, Induced subgraph density I, 4.2, internal claim (1).
Depends on
- Labelled blowup and good induced copy
- The product rule: $\lvert A \times B\rvert = \lvert A\rvert\,\lvert B\rvert$, and $\big\lvert\prod_{i<m} A_i\big\rvert = \prod_{i<m}\lvert A_i\rvert$
- The sum rule: a finite disjoint union is finite with $\lvert A \cup B\rvert = \lvert A\rvert + \lvert B\rvert$ and $\lvert\bigcup_{i \in I} A_i\rvert = \sum_{i \in I}\lvert A_i\rvert$, and a sum over a finite index set splits along a partition
- A subset of a finite set is finite, with $\lvert B\rvert \le \lvert A\rvert$, and equality holds if and only if $B = A$
Used by
Dependency tree · two levels
29 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
- Bucic, Nguyen, Scott and Seymour, Induced subgraph density I (standard reference, not scraped)