updates

content/Math4202/Math4202_L7.md

@@ -1,4 +1,4 @@
-# Math4202 Topology II (Lecture 6)
+# Math4202 Topology II (Lecture 7)
 
 ## Algebraic Topology
 
@@ -57,7 +57,7 @@ If $f:X\to Y$ is homotopy to a constant map. $f$ is called null homotopy.
 
 Let $f,f':I\to X$ be a continuous maps from an interval $I=[0,1]$ to a topological space $X$.
 
-Two pathes $f$ and $f'$ are path homotopic if 
+Two pathes $f$ and $f'$ are path homotopic if
 
 - there exists a continuous map $F:I\times [0,1]\to X$ such that $F(i,0)=f(i)$ and $F(i,1)=f'(i)$ for all $i\in I$.
-- $f(0)=f'(0)$ and $f(1)=f'(1)$.
+- $F(s,0)=f(0)$ and $F(s,1)=f(1)$, $\forall s\in I$.