# Suspensions of pointed types ```agda module synthetic-homotopy-theory.suspensions-of-pointed-types where ``` <details><summary>Imports</summary> ```agda open import foundation.constant-maps open import foundation.dependent-pair-types open import foundation.identity-types open import foundation.universe-levels open import structured-types.pointed-types open import synthetic-homotopy-theory.loop-spaces open import synthetic-homotopy-theory.suspension-structures open import synthetic-homotopy-theory.suspensions-of-types ``` </details> ## Idea When `X` is a pointed type, the suspension of `X` has nice properties ### The suspension of a pointed type ```agda suspension-Pointed-Type : {l : Level} → Pointed-Type l → Pointed-Type l pr1 (suspension-Pointed-Type X) = suspension (type-Pointed-Type X) pr2 (suspension-Pointed-Type X) = north-suspension ``` #### Suspension structure induced by a pointed type ```agda constant-suspension-structure-Pointed-Type : {l1 l2 : Level} (X : UU l1) (Y : Pointed-Type l2) → suspension-structure X (type-Pointed-Type Y) pr1 (constant-suspension-structure-Pointed-Type X Y) = point-Pointed-Type Y pr1 (pr2 (constant-suspension-structure-Pointed-Type X Y)) = point-Pointed-Type Y pr2 (pr2 (constant-suspension-structure-Pointed-Type X Y)) = const X refl ``` #### Suspension structure induced by a map into a loop space The following function takes a map `X → Ω Y` and returns a suspension structure on `Y`. ```agda module _ {l1 l2 : Level} (X : UU l1) (Y : Pointed-Type l2) where suspension-structure-map-into-Ω : (X → type-Ω Y) → suspension-structure X (type-Pointed-Type Y) pr1 (suspension-structure-map-into-Ω f) = point-Pointed-Type Y pr1 (pr2 (suspension-structure-map-into-Ω f)) = point-Pointed-Type Y pr2 (pr2 (suspension-structure-map-into-Ω f)) = f ```