typo

Author: GeoffreySangston

spaces/S000209/properties/P000216.md

@@ -9,4 +9,4 @@ The whole space is {P30} since {S209|P16}.
 And a proper open subset of $X$ is a disjoint union of open sets,
 each homeomorphic to either {S170}, {S25} or {S83}.
 Observe each of {S170|P30}, {S25|P30} and {S83|P30}.
-Since the {P30} property is perserved by taking disjoint unions, the result follows.
+Since the {P30} property is preserved by taking disjoint unions, the result follows.