Updated RS integral notation.

src/fa/rs/rs.tex

@@ -18,7 +18,7 @@
 
     Let $f: [a, b] \to E_2$, then $f$ is \textbf{Riemann-Stieltjes integrable} with respect to $G$ if the limit
     \[
-    \int_a^b f dG = \int_a^b f(t)dG(t) = \lim_{(P, c) \in \scp_t([a, b])}S(P, c, f, G)
+    \int_a^b f dG = \int_a^b f(t)G(dt) = \lim_{(P, c) \in \scp_t([a, b])}S(P, c, f, G)
     \]
     exists. In which case, $\int_a^b fdG$ is the \textbf{Riemann-Stieltjes integral} of $G$.