Alphabeta Math
DefinitionDefinition: Literature-sourcedProof: Not applicablejudge pass (gpt-5.6-terra)audited 2026-09-05
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.

Inverse image presheaf and inverse image sheaf

Definition

Let f:X→Y be a continuous map, and let G be a presheaf on Y. The inverse-image presheaf

fpG

on X is defined by

(fpG)(U):=lim→⁡f(U)⊆VG(V),

where V runs over the open neighbourhoods of f(U) in Y, ordered by reverse inclusion. If U′⊆U, then every neighbourhood of f(U) is a neighbourhood of f(U′), so there is a natural restriction map (fpG)(U)→(fpG)(U′).

The inverse image sheaf of a sheaf G on Y is the sheafification of this presheaf:

f−1G:=a(fpG).

When U is open in X and V is an open set of Y with f(U)⊆V, there is a canonical map

G(V)⟶(fpG)(U)

into the colimit class represented by V.

Depends on

Used by

Dependency tree · two levels

7 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