Skip to content

Commit

Permalink
renaming sets_of
Browse files Browse the repository at this point in the history
  • Loading branch information
zstone1 committed Mar 23, 2022
1 parent 2067a7a commit eec58b3
Show file tree
Hide file tree
Showing 2 changed files with 12 additions and 11 deletions.
4 changes: 2 additions & 2 deletions CHANGELOG_UNRELEASED.md
Original file line number Diff line number Diff line change
Expand Up @@ -55,8 +55,8 @@
+ globals `subspace_filter`, `subspace_proper_filter`
+ notation `{within ..., continuous ...}`
- in `topology.v`:
+ Definition `sets_of`
+ globals `sets_of_filter`,
+ Definition `powerset_filter_from`
+ globals `powerset_filter_from_filter`,
+ lemmas `near_small_set`, `small_set_sub`
+ lemmas `withinET`, `closureEcvg`, `entourage_sym`, `fam_nbhs`
+ generalize `cluster_cvgE`, `ptws_cvg_compact_family`
Expand Down
19 changes: 10 additions & 9 deletions theories/topology.v
Original file line number Diff line number Diff line change
Expand Up @@ -103,7 +103,7 @@ Require Import mathcomp_extra boolp reals classical_sets signed functions.
(* domain D. *)
(* subset_filter F D == similar to within D F, but with *)
(* dependent types. *)
(* sets_of F == The filter of downward closed subsets *)
(* powerset_filter_from F == The filter of downward closed subsets *)
(* of F. Enables use of near notation to *)
(* pick suitably small members of F *)
(* in_filter F == interface type for the sets that *)
Expand Down Expand Up @@ -1590,12 +1590,12 @@ Section NearSet.
Context {T : choiceType} {Y : filteredType T}.
Context (F : set (set Y)) (PF : ProperFilter F).

Definition sets_of : set (set (set Y)) := filter_from
Definition powerset_filter_from : set (set (set Y)) := filter_from
[set M | [/\ M `<=` F,
(forall E1 E2, M E1 -> F E2 -> E2 `<=` E1 -> M E2) & M !=set0 ] ]
id.

Global Instance sets_of_filter : ProperFilter sets_of.
Global Instance powerset_filter_from_filter : ProperFilter powerset_filter_from.
Proof.
split.
rewrite (_ : xpredp0 = set0); last by rewrite eqEsubset; split.
Expand All @@ -1615,10 +1615,11 @@ exists [set E | exists P Q, [/\ M P, N Q & E = P `&` Q] ]; first split.
by split; [apply: (subM _ _ MP) | apply: (subN _ _ MQ)] => // ? [].
Qed.

Lemma near_small_set : \forall E \near sets_of, F E.
Lemma near_small_set : \forall E \near powerset_filter_from, F E.
Proof. by exists F => //; split => //; exists setT; exact: filterT. Qed.

Lemma small_set_sub (E : set Y) : F E -> \forall E' \near sets_of, E' `<=` E.
Lemma small_set_sub (E : set Y) : F E ->
\forall E' \near powerset_filter_from, E' `<=` E.
Proof.
move=> entE; exists [set E' | F E' /\ E' `<=` E]; last by move=> ? [].
split; [by move=> E' [] | | by exists E; split].
Expand Down Expand Up @@ -2713,7 +2714,7 @@ Qed.
End Compact.
Arguments hausdorff_space : clear implicits.

Lemma near_compact_covering {X : topologicalType} {Y : topologicalType}
Lemma near_compact_covering {X : Type} {Y : topologicalType}
(F : set (set X)) (Q P : X -> Y -> Prop) (K : set Y) :
Filter F -> compact K ->
(forall y, K y -> \forall x \near F, Q x y) ->
Expand Down Expand Up @@ -6050,7 +6051,7 @@ Qed.
Definition pointwise_precompact {I} (W : set I) (d : I -> X -> Y) :=
forall x, precompact [set (d i x) | i in W].

Lemma pointwise_precomact_subset {I} (W V : set I) (fW fV : I -> (X -> Y)):
Lemma pointwise_precompact_subset {I J} (W : set I) (V : set J) {fW : I -> X -> Y} {fV : J -> X -> Y}:
fW @` W `<=` fV @` V -> pointwise_precompact V fV ->
pointwise_precompact W fW.
Proof.
Expand Down Expand Up @@ -6131,7 +6132,7 @@ apply/fam_cvgP => K ? U /=; rewrite uniform_nbhs => [[E [? EsubU]]].
suff : \forall g \near within W (nbhs f), forall y, K y -> E (f y, g y).
rewrite near_withinE; near_simpl => N; apply: (filter_app _ _ FW).
by apply ptwsF; near=> g => ?; apply EsubU; apply: (near N g).
near (sets_of (@entourage Y)) => E'.
near (powerset_filter_from (@entourage Y)) => E'.
have entE' : entourage E' by exact: (near (near_small_set _)).
pose Q := fun (h : X -> Y) x => E' (f x, h x).
apply: (@near_compact_covering _ _ _ Q) => //.
Expand Down Expand Up @@ -6178,7 +6179,7 @@ Lemma compact_equicontinuous (W : set {family compact, X -> Y}) :
Proof.
move=> lcptX ctsW cptW x E entE.
have [//|U UWx [cptU clU]] := lcptX x; rewrite withinET in UWx.
near (sets_of (@entourage Y)) => E'.
near (powerset_filter_from (@entourage Y)) => E'.
have entE' : entourage E' by exact: (near (near_small_set _)).
pose Q := fun (y : X) (f : {family compact, X -> Y}) => E' (f x, f y).
apply: (@near_compact_covering _ _ _ Q) => // f; rewrite /Q; near_simpl.
Expand Down

0 comments on commit eec58b3

Please sign in to comment.