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}}).
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}}.
diff --git a/theorems/T000822.md b/theorems/T000822.md
new file mode 100644
index 000000000..d33d388f8
--- /dev/null
+++ b/theorems/T000822.md
@@ -0,0 +1,12 @@
+---
+uid: T000822
+if:
+  P000154: true
+then:
+  P000207: true
+refs:
+  - mathse: 5117210
+    name: Is every orderable topology strongly collectionwise normal?
+---
+
+See {{mathse:5117210}}.