Update pval-h0.md

I think forth line of equation(3) should be F (probability distribution function), not a inverse function F

Author: Lo4ding00

P/pval-h0.md

@@ -52,7 +52,7 @@ $$ \label{eq:pval-cdf-s1}
 F_P(p) &= \mathrm{Pr}(P < p) \\
 &= \mathrm{Pr}(F_T(T) < p) \\
 &= \mathrm{Pr}(T < F_T^{-1}(p)) \\
-&= F_T^{-1}(F_T^{-1}(p)) \\
+&= F_T(F_T^{-1}(p)) \\
 &= p
 \end{split}
 $$
@@ -61,4 +61,4 @@ which is the [cumulative distribution function of a continuous uniform distribut
 
 $$ \label{eq:cuni-cdf}
 F_X(x) = \int_{-\infty}^{x} \mathcal{U}(z; 0, 1) \, \mathrm{d}z = x \quad \text{where} \quad 0 \leq x \leq 1 \; .
-$$
+$$