Closed sets #
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We define a few types of closed sets in a topological space.
Main Definitions #
For a topological space α
,
closeds α
: The type of closed sets.clopens α
: The type of clopen sets.
Closed sets #
The type of closed subsets of a topological space.
Instances for topological_space.closeds
Equations
- topological_space.closeds.set_like = {coe := topological_space.closeds.carrier _inst_1, coe_injective' := _}
The closure of a set, as an element of closeds
.
The galois coinsertion between sets and opens.
Equations
- topological_space.closeds.complete_lattice = topological_space.closeds.gi.lift_complete_lattice.copy complete_lattice.le topological_space.closeds.complete_lattice._proof_1 {carrier := set.univ α, closed' := _} topological_space.closeds.complete_lattice._proof_2 {carrier := ∅, closed' := _} topological_space.closeds.complete_lattice._proof_3 (λ (s t : topological_space.closeds α), {carrier := ↑s ∪ ↑t, closed' := _}) topological_space.closeds.complete_lattice._proof_5 (λ (s t : topological_space.closeds α), {carrier := ↑s ∩ ↑t, closed' := _}) topological_space.closeds.complete_lattice._proof_7 complete_lattice.Sup topological_space.closeds.complete_lattice._proof_8 (λ (S : set (topological_space.closeds α)), {carrier := ⋂ (s : topological_space.closeds α) (H : s ∈ S), ↑s, closed' := _}) topological_space.closeds.complete_lattice._proof_10
The type of closed sets is inhabited, with default element the empty set.
Equations
Equations
- topological_space.closeds.order.coframe = {sup := complete_lattice.sup topological_space.closeds.complete_lattice, le := complete_lattice.le topological_space.closeds.complete_lattice, lt := complete_lattice.lt topological_space.closeds.complete_lattice, le_refl := _, le_trans := _, lt_iff_le_not_le := _, le_antisymm := _, le_sup_left := _, le_sup_right := _, sup_le := _, inf := complete_lattice.inf topological_space.closeds.complete_lattice, inf_le_left := _, inf_le_right := _, le_inf := _, Sup := complete_lattice.Sup topological_space.closeds.complete_lattice, le_Sup := _, Sup_le := _, Inf := has_Inf.Inf (conditionally_complete_lattice.to_has_Inf (topological_space.closeds α)), Inf_le := _, le_Inf := _, top := complete_lattice.top topological_space.closeds.complete_lattice, bot := complete_lattice.bot topological_space.closeds.complete_lattice, le_top := _, bot_le := _, infi_sup_le_sup_Inf := _}
The term of closeds α
corresponding to a singleton.
Equations
- topological_space.closeds.singleton x = {carrier := {x}, closed' := _}
The complement of a closed set as an open set.
The complement of an open set as a closed set.
closeds.compl
as an order_iso
to the order dual of opens α
.
Equations
opens.compl
as an order_iso
to the order dual of closeds α
.
Equations
in a t1_space
, atoms of closeds α
are precisely the closeds.singleton
s.
in a t1_space
, coatoms of opens α
are precisely complements of singletons:
(closeds.singleton x).compl
.
Clopen sets #
The type of clopen sets of a topological space.
Instances for topological_space.clopens
- topological_space.clopens.has_sizeof_inst
- topological_space.clopens.set_like
- topological_space.clopens.has_sup
- topological_space.clopens.has_inf
- topological_space.clopens.has_top
- topological_space.clopens.has_bot
- topological_space.clopens.has_sdiff
- topological_space.clopens.has_compl
- topological_space.clopens.boolean_algebra
- topological_space.clopens.inhabited
Equations
- topological_space.clopens.set_like = {coe := λ (s : topological_space.clopens α), s.carrier, coe_injective' := _}
Reinterpret a compact open as an open.
Equations
- topological_space.clopens.has_compl = {compl := λ (s : topological_space.clopens α), {carrier := (↑s)ᶜ, clopen' := _}}
Equations
- topological_space.clopens.boolean_algebra = function.injective.boolean_algebra coe topological_space.clopens.boolean_algebra._proof_1 topological_space.clopens.boolean_algebra._proof_2 topological_space.clopens.boolean_algebra._proof_3 topological_space.clopens.boolean_algebra._proof_4 topological_space.clopens.boolean_algebra._proof_5 topological_space.clopens.boolean_algebra._proof_6 topological_space.clopens.boolean_algebra._proof_7