\begin{definition}[Definition:Definite Integral/Limits of Integration/Upper Limit]
Let $a, b \in \R$ be real numbers such that $a \le b$.
Let $f: \R \to \R$ be a real function.
Let the definite integral of $f$ {{WRT|Integration}} $x$ from $a$ to $b$ be:
:$\ds \int_a^b \map f x \rd x$
The limit $b$ is referred to as the '''upper limit''' of the integral'''.
\end{definition}