From 12d2091883685801f25ca1b0b7525db60e240f9b Mon Sep 17 00:00:00 2001
From: Moniker1998 <adamcz98333@gmail.com>
Date: Wed, 31 Dec 2025 19:00:14 +0100
Subject: [PATCH 1/3] two corollaries of Mansfield paper

---
 theorems/T000820.md | 12 ++++++++++++
 theorems/T000821.md | 14 ++++++++++++++
 2 files changed, 26 insertions(+)
 create mode 100644 theorems/T000820.md
 create mode 100644 theorems/T000821.md

diff --git a/theorems/T000820.md b/theorems/T000820.md
new file mode 100644
index 000000000..5538c5298
--- /dev/null
+++ b/theorems/T000820.md
@@ -0,0 +1,12 @@
+---
+uid: T000820
+if:
+  P000154: true
+then:
+  P000207: true
+refs:
+  - mathse: 5117210
+    name: Is every orderable topology strongly collectionwise normal?
+---
+
+See {{mathse:5117210}}.
diff --git a/theorems/T000821.md b/theorems/T000821.md
new file mode 100644
index 000000000..0074e1574
--- /dev/null
+++ b/theorems/T000821.md
@@ -0,0 +1,14 @@
+---
+uid: T000821
+if:
+  and:
+  - P000190: true
+  - P000030: true
+then:
+  P000017: true
+refs:
+  - mathse: 5117210
+    name: Is every orderable topology strongly collectionwise normal?
+---
+
+See {{mathse:5117210}}.

From 2fc4172afffb01e3515d892e622d1b82f649c3d3 Mon Sep 17 00:00:00 2001
From: Moniker1998 <88507423+Moniker1998@users.noreply.github.com>
Date: Fri, 2 Jan 2026 13:58:15 +0100
Subject: [PATCH 2/3] changed name of theorem

---
 theorems/{T000820.md => T000822.md} | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
 rename theorems/{T000820.md => T000822.md} (92%)

diff --git a/theorems/T000820.md b/theorems/T000822.md
similarity index 92%
rename from theorems/T000820.md
rename to theorems/T000822.md
index 5538c5298..d33d388f8 100644
--- a/theorems/T000820.md
+++ b/theorems/T000822.md
@@ -1,5 +1,5 @@
 ---
-uid: T000820
+uid: T000822
 if:
   P000154: true
 then:

From 68cf506cab7219f9ee4fadc9ffb26ebcffbc4b40 Mon Sep 17 00:00:00 2001
From: Moniker1998 <adamcz98333@gmail.com>
Date: Sat, 10 Jan 2026 19:39:46 +0100
Subject: [PATCH 3/3] add meta-property

---
 properties/P000207.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/properties/P000207.md b/properties/P000207.md
index 1d7d41f04..a18b03e6d 100644
--- a/properties/P000207.md
+++ b/properties/P000207.md
@@ -31,3 +31,4 @@ See also {{doi:10.1090/S0002-9939-1981-0630058-4}}.
 #### Meta-properties
 
 - This property is preserved by arbitrary disjoint unions.
+- This property is hereditary with respect to closed sets (corollary of theorem 4.1 in {{doi:10.2307/1993026}}).