Adds Hatcher as ref for locally contractible (P223)

GeoffreySangston · web-flow · commit f1fb3db2241f · 2026-04-04T12:22:21.000-04:00
diff --git a/properties/P000223.md b/properties/P000223.md
@@ -1,8 +1,11 @@
 ---
 uid: P000223
 name: Locally contractible
+refs:
+  - zb: "1044.55001"
+    name: Algebraic Topology (Hatcher)
 ---
 
 $X$ admits a basis of open sets which are {P199}.
 
-The naming of this property follows pi-base conventions.
+The naming of this property follows pi-base conventions. Defined in Proposition A.4 of {{zb:"1044.55001"}}. 
