Pointed types
module structured-types.pointed-types where
Idea
A pointed type is a type A
equipped with an element a : A
.
Definition
The universe of pointed types
Pointed-Type : (l : Level) → UU (lsuc l) Pointed-Type l = Σ (UU l) (λ X → X) module _ {l : Level} (A : Pointed-Type l) where type-Pointed-Type : UU l type-Pointed-Type = pr1 A point-Pointed-Type : type-Pointed-Type point-Pointed-Type = pr2 A
Evaluation at the base point
ev-point-Pointed-Type : {l1 l2 : Level} (A : Pointed-Type l1) {B : UU l2} → (type-Pointed-Type A → B) → B ev-point-Pointed-Type A f = f (point-Pointed-Type A)
See also
-
The notion of nonempty types is treated in
foundation.empty-types
. -
The notion of inhabited types is treated in
foundation.inhabited-types
.