proof format updates using gfm

content/CSE442T/CSE442T_L15.md

@@ -115,7 +115,8 @@ $$
 
 #### Theorem PRG exists then PRF family exists.
 
-Proof:
+<details>
+<summary>Proof</summary>
 
 Let $g:\{0,1\}^n\to \{0,1\}^{2n}$ be a PRG.
 
@@ -184,6 +185,6 @@ Assume that $D$ distinguishes $f_s$ and $F\gets RF_n$ with non-negligible probab
 
 By hybrid argument, there exists a hybrid $H_i$ such that $D$ distinguishes $H_i$ and $H_{i+1}$ with non-negligible probability.
 
-For $H_0$, 
+For $H_0$, $D$ distinguishes $H_0$ and $H_1$ with non-negligible probability.
 
-QED
+</details>