commit 12e3092a1779d41507e1eb4a3fe867fc716673af Author: Leon Vatthauer Date: Sat May 4 14:15:13 2024 +0200 initial diff --git a/Algebra/GSet.agda b/Algebra/GSet.agda new file mode 100644 index 0000000..14004a9 --- /dev/null +++ b/Algebra/GSet.agda @@ -0,0 +1,28 @@ +open import Algebra.Bundles +open import Level +open import Data.Product +open import Relation.Binary.PropositionalEquality + +module GSet {c ℓ : Level} where + open Group using () renaming (Carrier to ∣_∣) + record G-Set (G : Group c ℓ) : Set (suc (c ⊔ ℓ)) where + open Group G using (ε; _∙_) + field + X : Set c + _⊳_ : ∣ G ∣ → X → X + field + ε⊳ : ∀ {x : X} → ε ⊳ x ≡ x + ∘⊳ : ∀ {g h : ∣ G ∣} {x : X} → (g ∙ h) ⊳ x ≡ (g ⊳ (h ⊳ x)) + + open G-Set using () renaming (X to ∣_∣) + + isEquivariant : ∀ {G : Group c ℓ} (X Y : G-Set G) (f : ∣ X ∣ → ∣ Y ∣) → Set c + isEquivariant {G} X Y f = ∀ {g : ∣ G ∣} {x : ∣ X ∣} → f (g ⊳ˣ x) ≡ g ⊳ʸ (f x) + where + open G-Set X using () renaming (_⊳_ to _⊳ˣ_) + open G-Set Y using () renaming (_⊳_ to _⊳ʸ_) + + record G-Set-Morphism (G : Group c ℓ) (X Y : G-Set G) : Set (suc (c ⊔ ℓ)) where + field + f : ∣ X ∣ → ∣ Y ∣ + isEqui : isEquivariant X Y f diff --git a/Category/GSets.agda b/Category/GSets.agda new file mode 100644 index 0000000..4fcd00f --- /dev/null +++ b/Category/GSets.agda @@ -0,0 +1,2 @@ +open import Algebra.Bundles +open import Level diff --git a/gset.agda-lib b/gset.agda-lib new file mode 100644 index 0000000..f075a25 --- /dev/null +++ b/gset.agda-lib @@ -0,0 +1,3 @@ +name: gset +include: . +depend: agda-categories standard-library