updates

content/Math4202/Exam_reviews/Math4202_E1.md

@@ -163,9 +163,9 @@ Define the product $f*g$ of $f$ and $g$ to be the map $h:[0,1]\to X$.
 
 #### Definition for equivalent classes of paths
 
-$\Pi_1(X,x)$ is the equivalent classes of paths starting and ending at $x$.
+$pi_1(X,x)$ is the equivalent classes of paths starting and ending at $x$.
 
-On $\Pi_1(X,x)$,, we define $\forall [f],[g],[f]*[g]=[f*g]$.
+On $pi_1(X,x)$,, we define $\forall [f],[g],[f]*[g]=[f*g]$.
 
 $$
 [f]\coloneqq \{f_i:[0,1]\to X|f_0(0)=f(0),f_i(1)=f(1)\}