minor tweak

Author: prabau

theorems/T000172.md

@@ -8,7 +8,7 @@ then:
 
 After Player 1 chooses an open set $U_0$ and a point $x_0\in U_0$,
 Player 2 can choose a open neighborhood $V_0\subseteq U_0$ of $x_0$
-with $V_0$ homeomorphic to some $\mathbb R^n$ or $\mathbb R^n_+$.
+homeomorphic to some $\mathbb R^n$ or $\mathbb R^n_+$.
 The rest of the game is played on $V_0$ and Player 2 has a winning strategy
 since $\mathbb R^n$ and $\mathbb R^n_+$ are both {P206}
 [(Explore)](https://topology.pi-base.org/spaces?q=Completely+metrizable+%2B+%7EStrongly+Choquet).