adding an explanatory text with makeidx in a book document class

Question

(SECOND POST) Here is an updated code which shows that when commenting the index package I get in the index two separate entries in the index for the term alldifferent (one for its definition and one for its occurrence). But if I put the index package I get only one entry for alldifferent (as it should be), but I dont get the explanatory text anymore.

\documentclass[]{book}

\usepackage{etex}
\usepackage{makeidx}
\usepackage[totoc,columns=1]{idxlayout}
%\usepackage{index}
\usepackage[plainpages=false,pdfpagelabels,colorlinks,linkcolor=cyan,citecolor=cyan,urlcolor=cyan,bookmarks,hyperindex=false,pagebackref=true]{hyperref}

\sloppy
\makeindex

\newcommand*{\indexuse}[1]{\hyperpage{#1}}
\newcommand*{\indexdef}[1]{\textbf{\hyperpage{#1}}}
\newcommand*{\indexsyn}[1]{\textbf{\textit{\hyperpage{#1}}}}

\def\constraint#1{\textsc{#1}}
\def\ctrref#1{$\constraint{#1}$\index{#1@$\constraint{#1}$|indexuse}}

\pagestyle{headings}

\begin{document}

\pagenumbering{Alph}% to avoid spurious warnings
\title{\Huge Title}
\author{toto}
\maketitle
\thispagestyle{empty}

\frontmatter

\tableofcontents

\chapter{Preface}

abc abc
toto \index{toto|indexuse}
def
\index{alldifferent@$\constraint{alldifferent}$|indexdef}

\mainmatter
\chapter{First chapter}

tutu \index{tutu|indexuse}
titi \index{titi|indexuse}
aaa aaa \index{toto|indexdef} bbb


tutu \index{tutu|indexdef}
titi \index{titi|indexdef}
\index{toto|indexsyn}
\ctrref{alldifferent}


\setindexprenote{%
  Page numbers in bold face (as in \textbf{160}) point to a definition
  of a constraint, keyword, restriction or system. Page numbers in
  bold-italic face (as in \textbf{\textit{160}}) notify an abbreviation
  of a constraint name. Finally, page numbers in serif face (as in 160) 
  indicate an occurrence of constraint name, keyword, system or author name.%
}
\printindex
\end{document}

(INITIAL POST) Is there a way to add an explanatory small text to an index page when using makeidx together with the book class (note that since I am using an .ist style file I prefer to stay with makeidx and not to use the splitidx or imakeidx packages suggested in some posts; since I also use the book class I dont want to switch to the memoir class as suggested in some other post).

Since I am not completely sure where to exactly add your suggested code, I add a tiny example of my document that compile:

\documentclass[]{book}
\usepackage{makeidx}
\usepackage{index}
\usepackage[plainpages=false,pdfpagelabels,colorlinks,linkcolor=cyan,
            citecolor=cyan,urlcolor=cyan,bookmarks,
            hyperindex=false,pagebackref=true]{hyperref} 

\sloppy
\makeindex

\newcommand*{\indexuse}[1]{\hyperpage{#1}}

\begin{document}

\pagestyle{headings}
\title{\Huge Title}
\author{toto}
\maketitle
\thispagestyle{empty}

\frontmatter
\chapter{Preface}

abc abc
toto \index{toto|indexuse}
def

\mainmatter
\chapter{First chapter}

tutu \index{tutu|indexuse}
titi \index{titi|indexuse}

\cleardoublepage
\markboth{INDEX}{INDEX}
\phantomsection
\addcontentsline{toc}{chapter}{Index}
% Page numbers in bold face (as in \textbf{160}) point to a definition
% of a constraint, keyword, restriction or system. Page numbers in
% bold-italic face (as in \textbf{\textit{160}}) notify an abbreviation
% of a constraint name. Finally, page numbers in serif face (as in 160) 
% indicate an occurrence of constraint name, keyword, system or author name.
\printindex
\end{document}

Finally the catalog.ist file contains the following lines:

preamble "\\begin{theindex} {\\small\\onecolumn\\newcounter{idxl}\n"
postamble "\n\n} \\end{theindex} \n"
group_skip "\n\n  \\vspace*{12mm}\n"
heading_prefix "{
\\bfseries\\Large\\hfill "
heading_suffix "\\hfill}\\nopagebreak\\vspace*{4mm}\\stepcounter{idxl}\n"
symhead_positive "1..."
headings_flag  1

Answer 1

You can use idxlayout, which also makes it possible to avoid issuing \onecolumn. Here's the fixed .ist file:

preamble "\\begin{theindex} \\small\\newcounter{idxl}\n"
postamble "\n\n \\end{theindex} \n"
group_skip "\n\n  \\vspace*{12mm}\n"
heading_prefix "{\\bfseries\\Large\\hfill "
heading_suffix "\\hfill}\\nopagebreak\\vspace*{4mm}\\stepcounter{idxl}\n"
symhead_positive "1..."
headings_flag  1

Here's the example, where I have populated the index to show how the headers and the entry in the table of contents are as wanted.

\documentclass[]{book}
\usepackage{makeidx}
%\usepackage{index} % do you need it?
\usepackage[totoc,columns=1]{idxlayout}
\usepackage[
  plainpages=false,
  pdfpagelabels,
  colorlinks,
  linkcolor=cyan,
  citecolor=cyan,
  urlcolor=cyan,
  bookmarks,
  hyperindex=false,
  pagebackref=true,
]{hyperref} 

\sloppy
\makeindex

\newcommand*{\indexuse}[1]{\hyperpage{#1}}

\pagestyle{headings}

\begin{document}

\pagenumbering{Alph}% to avoid spurious warnings
\title{\Huge Title}
\author{toto}
\maketitle
\thispagestyle{empty}

\frontmatter

\tableofcontents

\chapter{Preface}

abc abc
toto \index{toto|indexuse}
def

\mainmatter
\chapter{First chapter}

tutu \index{tutu|indexuse}
titi \index{titi|indexuse}

% populate the index
\count255=0
\loop\ifnum\count255<200
  \advance\count255 1
  \expandafter\index\expandafter{\romannumeral\count255|indexuse}
\repeat

\setindexprenote{%
  Page numbers in bold face (as in \textbf{160}) point to a definition
  of a constraint, keyword, restriction or system. Page numbers in
  bold-italic face (as in \textbf{\textit{160}}) notify an abbreviation
  of a constraint name. Finally, page numbers in serif face (as in 160) 
  indicate an occurrence of constraint name, keyword, system or author name.%
}
\printindex
\end{document}

Answer 2

You don't need any special packages for this. makeindex just writes \begin{theindex} ... \end{theindex} into the .ind file so you just define that environment to do whatever you want This is the definition from article.cls with a paragraph of text added

\renewenvironment{theindex}
               {\if@twocolumn
                  \@restonecolfalse
                \else
                  \@restonecoltrue
                \fi
                \twocolumn[\section*{\indexname}
this is a paragraph spanning a 2-column index

a second paragraph
]%
            \@mkboth{\MakeUppercase\indexname}%
                    {\MakeUppercase\indexname}%

  this is a paragraph in the first column of the index

            \thispagestyle{plain}\parindent\z@
            \parskip\z@ \@plus .3\p@\relax
            \columnseprule \z@
            \columnsep 35\p@
            \let\item\@idxitem}
           {\if@restonecol\onecolumn\else\clearpage\fi}

Seeing this in context of the example you added later, note i removed a bad group and\clearpage` from the ist file.

document

\documentclass[]{book}
\usepackage{makeidx}
\usepackage{index}
\usepackage[plainpages=false,pdfpagelabels,colorlinks,linkcolor=cyan,
            citecolor=cyan,urlcolor=cyan,bookmarks,
            hyperindex=false,pagebackref=true]{hyperref} 

\sloppy
\makeindex

\makeatletter
\newcounter{idxl}
\renewenvironment{theindex}
               {\if@twocolumn
                  \@restonecolfalse
                \else
                  \@restonecoltrue
                \fi
                \twocolumn[\section*{\indexname}
this is a paragraph spanning a 2-column index

a second paragraph
]%
            \@mkboth{\MakeUppercase\indexname}%
                    {\MakeUppercase\indexname}%

  this is a paragraph in the first column of the index

            \thispagestyle{plain}\parindent\z@
            \parskip\z@ \@plus .3\p@\relax
            \columnseprule \z@
            \columnsep 35\p@
            \let\item\@idxitem}
           {\if@restonecol\onecolumn\else\clearpage\fi}
\makeatother
\newcommand*{\indexuse}[1]{\hyperpage{#1}}

\begin{document}

\pagestyle{headings}
\title{\Huge Title}
\author{toto}
\maketitle
\thispagestyle{empty}

\frontmatter
\chapter{Preface}

abc abc
toto \index{toto|indexuse}
def

\mainmatter
\chapter{First chapter}

tutu \index{tutu|indexuse}
titi \index{titi|indexuse}

\cleardoublepage
\markboth{INDEX}{INDEX}
\phantomsection
\addcontentsline{toc}{chapter}{Index}
% Page numbers in bold face (as in \textbf{160}) point to a definition
% of a constraint, keyword, restriction or system. Page numbers in
% bold-italic face (as in \textbf{\textit{160}}) notify an abbreviation
% of a constraint name. Finally, page numbers in serif face (as in 160) 
% indicate an occurrence of constraint name, keyword, system or author name.
\printindex
\end{document}

ist

preamble "\\begin{theindex} 
postamble "\n\n} \\end{theindex} \n"
group_skip "\n\n  \\vspace*{12mm}\n"
heading_prefix "{
\\bfseries\\Large\\hfill "
heading_suffix "\\hfill}\\nopagebreak\\vspace*{4mm}\\stepcounter{idxl}\n"
symhead_positive "1..."
headings_flag  1