docs(manual): fix duplicate labels and correct section hierarchy

Author: tueda

doc/manual/functions.tex

@@ -1302,7 +1302,7 @@ \section{thetap\_}\index{thetap\_}\index{function!thetap\_}
 %--#[ tofloat_ :
 
 \section{tofloat\_}\index{tofloat\_}\index{function!tofloat\_}
-\label{funmatch}
+\label{funtofloat}
 \noindent Currently not active.
 
 %--#] tofloat_ : 
@@ -1317,7 +1317,7 @@ \section{topologies\_}\index{topologies\_}\index{function!topologies\_}
 %--#[ torat_ :
 
 \section{torat\_}\index{torat\_}\index{function!torat\_}
-\label{funmatch}
+\label{funtorat}
 \noindent Currently not active.
 
 %--#] torat_ : 

doc/manual/optim.tex

@@ -123,7 +123,7 @@ \chapter{Output optimization}
 regular printing of the output this is not needed because the expression 
 itself remains in its unoptimized version.
 
-\subsection{Optimization options of the Format statement}
+\section{Optimization options of the Format statement}
 
 The \verb|Format| statement has a number of options to control the
 code optimization. The easiest to use are the following:

doc/manual/statements.tex

@@ -552,7 +552,7 @@ \section{chisholm}
 %--#] chisholm : 
 %--#[ chop :
 \section{chop}
-\label{substaevaluate}
+\label{substachop}
 
 \noindent \begin{tabular}{ll}
 Type & Executable statement\\
@@ -5331,7 +5331,7 @@ \section{splitlastarg}
 %--#] splitlastarg : 
 %--#[ strictrounding :
 \section{strictrounding}
-\label{substaevaluate}
+\label{substastrictrounding}
 
 \noindent \begin{tabular}{ll}
 Type & Executable statement\\