From b10b4fcad19044ae9ed8562abcd74dd176eee725 Mon Sep 17 00:00:00 2001 From: yhx-12243 Date: Fri, 16 Jan 2026 08:01:55 +0800 Subject: [PATCH 1/4] =?UTF-8?q?Has=20closed=20discrete=20subset=20of=20siz?= =?UTF-8?q?e=20=F0=9D=94=A0=20(part=203)?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- spaces/S000060/properties/P000032.md | 16 ---------------- spaces/S000070/properties/P000032.md | 10 ---------- spaces/S000074/properties/P000032.md | 10 ---------- theorems/T000309.md | 18 ++++++++++++++++++ 4 files changed, 18 insertions(+), 36 deletions(-) delete mode 100644 spaces/S000060/properties/P000032.md delete mode 100644 spaces/S000070/properties/P000032.md delete mode 100644 spaces/S000074/properties/P000032.md create mode 100644 theorems/T000309.md diff --git a/spaces/S000060/properties/P000032.md b/spaces/S000060/properties/P000032.md deleted file mode 100644 index 5bd56ca4e..000000000 --- a/spaces/S000060/properties/P000032.md +++ /dev/null @@ -1,16 +0,0 @@ ---- -space: S000060 -property: P000032 -value: false ---- - -Take any countable partition $\{A_n:n<\omega\}$ of $\mathbb R\setminus\mathbb Q$ into Euclidean-dense subsets. -Then $\mathscr U:=\{A_n\cup\mathbb Q: n<\omega\}$ is -a countable open cover of $X$. Let $\mathscr V$ be an open refinement of $\mathscr U$. -Let $U$ be any neighbourhood of $x\in\mathbb R\setminus\mathbb Q$. The closure of $U$ contains an -interval around $x$, hence for each $n<\omega$ there exists -$a_n\in A_n\cap \overline{U}$. -If $a_n\in V\in\mathscr V$, the open set $V$ intersects $U$. -Note that each $a_n$ is contained in a different element of $\mathscr V$. -Therefore $U$ intersects infinitely many elements of $\mathscr V$, -proving $\mathscr V$ is not locally finite. diff --git a/spaces/S000070/properties/P000032.md b/spaces/S000070/properties/P000032.md deleted file mode 100644 index 1a7131dd9..000000000 --- a/spaces/S000070/properties/P000032.md +++ /dev/null @@ -1,10 +0,0 @@ ---- -space: S000070 -property: P000032 -value: false -refs: -- zb: "0386.54001" - name: Counterexamples in Topology ---- - -See item #8 for space #78 in {{zb:0386.54001}}. diff --git a/spaces/S000074/properties/P000032.md b/spaces/S000074/properties/P000032.md deleted file mode 100644 index 380aabcb6..000000000 --- a/spaces/S000074/properties/P000032.md +++ /dev/null @@ -1,10 +0,0 @@ ---- -space: S000074 -property: P000032 -value: false -refs: -- zb: "0386.54001" - name: Counterexamples in Topology ---- - -See item #7 for space #82 in {{zb:0386.54001}}. diff --git a/theorems/T000309.md b/theorems/T000309.md new file mode 100644 index 000000000..432bc9e3a --- /dev/null +++ b/theorems/T000309.md @@ -0,0 +1,18 @@ +--- +uid: T000309 +if: + and: + - P000026: true + - P000227: true +then: + P000032: false +refs: + - zb: "0684.54001" + name: General Topology (Engelking, 1989) + - zb: "1116.54006" + name: Normality and countable paracompactness of hyperspaces of ordinals. (Kemoto, Nobuyuki) +--- + +See Exercise 5.2.C(b) in {{zb:0684.54001}}. + +See also Claim in {{zb:1116.54006}}. From 0d2bae645b2cf6e2c6a7c80bee7415b1e2858c7c Mon Sep 17 00:00:00 2001 From: Patrick Rabau <70125716+prabau@users.noreply.github.com> Date: Fri, 16 Jan 2026 14:51:50 -0500 Subject: [PATCH 2/4] T309 -> T838 --- theorems/{T000309.md => T000838.md} | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) rename theorems/{T000309.md => T000838.md} (96%) diff --git a/theorems/T000309.md b/theorems/T000838.md similarity index 96% rename from theorems/T000309.md rename to theorems/T000838.md index 432bc9e3a..31492b7a6 100644 --- a/theorems/T000309.md +++ b/theorems/T000838.md @@ -1,5 +1,5 @@ --- -uid: T000309 +uid: T000838 if: and: - P000026: true From 0b077a2b8335e56e2080c2e9e7907e0fe4894d13 Mon Sep 17 00:00:00 2001 From: yhx-12243 Date: Tue, 20 Jan 2026 13:47:42 +0800 Subject: [PATCH 3/4] Update theorems/T000838.md Co-authored-by: Patrick Rabau <70125716+prabau@users.noreply.github.com> --- theorems/T000838.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/theorems/T000838.md b/theorems/T000838.md index 31492b7a6..568d24a06 100644 --- a/theorems/T000838.md +++ b/theorems/T000838.md @@ -15,4 +15,4 @@ refs: See Exercise 5.2.C(b) in {{zb:0684.54001}}. -See also Claim in {{zb:1116.54006}}. +See also the Claim on page 359 of {{zb:1116.54006}}. From 5cc4c9df8283a8fe3c7d069dfa3ec170b3125182 Mon Sep 17 00:00:00 2001 From: yhx-12243 Date: Tue, 20 Jan 2026 13:48:51 +0800 Subject: [PATCH 4/4] Update T000838.md --- theorems/T000838.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/theorems/T000838.md b/theorems/T000838.md index 568d24a06..b00e53cfe 100644 --- a/theorems/T000838.md +++ b/theorems/T000838.md @@ -10,7 +10,7 @@ refs: - zb: "0684.54001" name: General Topology (Engelking, 1989) - zb: "1116.54006" - name: Normality and countable paracompactness of hyperspaces of ordinals. (Kemoto, Nobuyuki) + name: Normality and countable paracompactness of hyperspaces of ordinals. (N. Kemoto) --- See Exercise 5.2.C(b) in {{zb:0684.54001}}.