From c6d2ea9618e391d98ae1a5f37443d8f95d35795f Mon Sep 17 00:00:00 2001 From: Patrick Rabau <70125716+prabau@users.noreply.github.com> Date: Tue, 27 Jan 2026 20:06:44 -0500 Subject: [PATCH 1/4] Locally orderable spaces are radial --- properties/P000172.md | 4 ++++ theorems/T000774.md | 14 ++++++++++++++ 2 files changed, 18 insertions(+) create mode 100644 theorems/T000774.md diff --git a/properties/P000172.md b/properties/P000172.md index 53dba5c78b..d600a1e90a 100644 --- a/properties/P000172.md +++ b/properties/P000172.md @@ -19,3 +19,7 @@ Compare with {P80}. - This property is hereditary. - $X$ satisfies this property iff its Kolmogorov quotient $\text{Kol}(X)$ does. +- A space that is locally {P172} (every point has a neighborhood with the property) +has the property. +- This property is not preserved by products +(Example: {S78|P172}). diff --git a/theorems/T000774.md b/theorems/T000774.md new file mode 100644 index 0000000000..f75f5747ed --- /dev/null +++ b/theorems/T000774.md @@ -0,0 +1,14 @@ +--- +uid: T000774 +if: + P000120: true +then: + P000172: true +--- + +Let $A\subseteq X$ and $p\in\overline A$. +Since $X$ is {P120}, $p$ has an open neighborhood $U$ +that is orderable ({P133}), and hence also {P172} +[(Explore)](https://topology.pi-base.org/spaces?q=LOTS%2B%7ERadial). +Because $p\in\overline{A\cap U}$, and thus $p\in\text{cl}_U(A\cap U)$, +it follows that there is a transfinite sequence of points of $A\cap U$ converging to $p$. From cd9f80a77814abbb6938e47b437a9fcc11adb840 Mon Sep 17 00:00:00 2001 From: Patrick Rabau <70125716+prabau@users.noreply.github.com> Date: Tue, 27 Jan 2026 23:05:09 -0500 Subject: [PATCH 2/4] renumber thm --- theorems/{T000774.md => T000839.md} | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) rename theorems/{T000774.md => T000839.md} (97%) diff --git a/theorems/T000774.md b/theorems/T000839.md similarity index 97% rename from theorems/T000774.md rename to theorems/T000839.md index f75f5747ed..ad0b34ffc5 100644 --- a/theorems/T000774.md +++ b/theorems/T000839.md @@ -1,5 +1,5 @@ --- -uid: T000774 +uid: T000839 if: P000120: true then: From 4aa47a5c9b2992a9e47263329f76154207b63c62 Mon Sep 17 00:00:00 2001 From: Patrick Rabau <70125716+prabau@users.noreply.github.com> Date: Tue, 27 Jan 2026 23:31:38 -0500 Subject: [PATCH 3/4] simplification --- theorems/T000839.md | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/theorems/T000839.md b/theorems/T000839.md index ad0b34ffc5..bb772d2e3f 100644 --- a/theorems/T000839.md +++ b/theorems/T000839.md @@ -6,9 +6,6 @@ then: P000172: true --- -Let $A\subseteq X$ and $p\in\overline A$. -Since $X$ is {P120}, $p$ has an open neighborhood $U$ -that is orderable ({P133}), and hence also {P172} +This follows from the fact that {P172} is a "local" property, +and {P133} spaces are {P172} [(Explore)](https://topology.pi-base.org/spaces?q=LOTS%2B%7ERadial). -Because $p\in\overline{A\cap U}$, and thus $p\in\text{cl}_U(A\cap U)$, -it follows that there is a transfinite sequence of points of $A\cap U$ converging to $p$. From 3280c4f5e31c3784b060d974378c3545fe2c36fb Mon Sep 17 00:00:00 2001 From: Patrick Rabau <70125716+prabau@users.noreply.github.com> Date: Thu, 29 Jan 2026 16:23:23 -0500 Subject: [PATCH 4/4] simplification --- properties/P000172.md | 3 +-- theorems/T000839.md | 3 +-- 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/properties/P000172.md b/properties/P000172.md index d600a1e90a..545886d9a2 100644 --- a/properties/P000172.md +++ b/properties/P000172.md @@ -19,7 +19,6 @@ Compare with {P80}. - This property is hereditary. - $X$ satisfies this property iff its Kolmogorov quotient $\text{Kol}(X)$ does. -- A space that is locally {P172} (every point has a neighborhood with the property) -has the property. +- If each point has a neighborhood with the property, $X$ also has the property. - This property is not preserved by products (Example: {S78|P172}). diff --git a/theorems/T000839.md b/theorems/T000839.md index bb772d2e3f..e7b94975eb 100644 --- a/theorems/T000839.md +++ b/theorems/T000839.md @@ -6,6 +6,5 @@ then: P000172: true --- -This follows from the fact that {P172} is a "local" property, -and {P133} spaces are {P172} +Each point has a neighborhood that is {P133} and hence {P172} [(Explore)](https://topology.pi-base.org/spaces?q=LOTS%2B%7ERadial).