[qty.expr.temp.algo] Detail first step example

docs/api_reference/src/quantities.tex

@@ -916,8 +916,19 @@
 Otherwise, a type $x$ is an input symbolic constant.
 \end{itemize}
 \begin{example}
-The input of \tcode{derived_unit<si::kilo_<si::metre>, per<power<non_si::hour, 2>>>}
-is $\tcode{km}/\tcode{h}^2$.
+Item by item, this algorithm step goes from the \Cpp{} parameter type
+\tcode{derived_unit<si::kilo_<si::metre>, per<power<non_si::hour, 2>>}
+\begin{itemize}
+\item
+to $\tcode{si::kilo_<si::metre>} \times \tcode{per<power<non_si::hour, 2>}$ (product of \tcode{To}'s arguments),
+\item
+to $\tcode{si::kilo_<si::metre>} \times 1/\tcode{power<non_si::hour, 2>}$ (product of \tcode{per}'s arguments as denominator),
+\item
+to $\tcode{si::kilo_<si::metre>} \times 1/\tcode{non_si::hour}^2$ (\tcode{power}s as powers),
+\item
+to $x \times 1/y^2$ where $x = \tcode{si::kilo_<si::metre>}$ and $y = \tcode{non_si::hour}$ (symbolic substitution)
+in the mathematical domain.
+\end{itemize}
 \end{example}
 
 \pnum