mathlib documentation

topology.​category.​Top.​basic

topology.​category.​Top.​basic

def Top  :
Type (u+1)

The category of topological spaces and continuous maps.

Equations
@[simp]
theorem Top.​id_app (X : Top) (x : X) :
(𝟙 X) x = x

@[simp]
theorem Top.​comp_app {X Y Z : Top} (f : X Y) (g : Y Z) (x : X) :
(f g) x = g (f x)

def Top.​of (X : Type u) [topological_space X] :

Construct a bundled Top from the underlying type and the typeclass.

Equations
def Top.​discrete  :
Type u Top

The discrete topology on any type.

Equations
def Top.​trivial  :
Type u Top

The trivial topology on any type.

Equations