Theorems · Definition · category theory
TopCat.Presheaf.IsSheafPairwiseIntersections
{C : Type u_1} → [inst : CategoryTheory.Category.{v_1, u_1} C] → {X : TopCat} → TopCat.Presheaf C X → PropAn alternative formulation of the sheaf condition
(which we prove equivalent to the usual one below as
isSheaf_iff_isSheafPairwiseIntersections).
A presheaf is a sheaf if F sends the cone (Pairwise.cocone U).op to a limit cone.
(Recall Pairwise.cocone U has cone point iSup U, mapping down to the U i and the U i ⊓ U j.)
- Cited by
- 3 results in Mathlib
- Foundations
- Depth 71 from the axioms · uses propext, Classical.choice, Quot.sound
- Assumes
- CategoryTheory.Category
Around this declaration
Dashed lines are statement dependencies; solid lines are citations in proofs.
Cites9
Mathlib declarations this one mentions in its statement or cites explicitly in its proof. Plumbing is filtered out.
- CategoryTheory.Categorystatement and proof · cited by 32,673
- TopCat.carrierproof · cited by 3,184
- TopologicalSpace.Opensproof · cited by 2,040
- TopCatstatement and proof · cited by 1,889
- CategoryTheory.Limits.IsLimitproof · cited by 664
- TopCat.Presheafstatement and proof · cited by 371
- CategoryTheory.Functor.mapConeproof · cited by 147
- CategoryTheory.Limits.Cocone.opproof · cited by 38
- CategoryTheory.Pairwise.coconeproof · cited by 8
Cited by3
Results whose statement or proof uses this declaration.
- TopCat.Presheaf.isSheaf_iff_isSheafPairwiseIntersectionsstatement and proof · cited by 4
- TopCat.Presheaf.isSheafOpensLeCover_iff_isSheafPairwiseIntersectionsstatement · cited by 1
- TopCat.Presheaf.isSheaf_iff_isSheafEqualizerProductsproof · cited by 0