Update properties/P000207.md

Author: prabau

properties/P000207.md

@@ -31,4 +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 {{zb:0078.14803}}).
+- This property is hereditary with respect to closed sets (corollary of Theorem 4.1 in {{zb:0078.14803}}).