<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">For a while I thought I had traced the source of the error to what _was_ an unmatched “$” in:<div class=""><br class=""></div><div class=""><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">\renewcommand{\indexname}{Index}</font></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">\renewcommand{\preindexhook}{%</font></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">\emph{%</font></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">For $d\text{\emph{-ball}}$, $d\text{\emph{-bounded set}}$, $d\text{\emph{-open set}}$, $(d,\,d')\text{\emph{-continuous map}}$, etc., see the corresponding entry \emph{ball, bounded set, open set, continuous map,} etc.%</font></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">\vskip\onelineskip}%</font></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">}</font></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">\printindex</font></div><div style="margin: 0px; font-stretch: normal; font-size: 18px; line-height: normal;" class=""><br class=""></div><div style="margin: 0px; font-stretch: normal; font-size: 18px; line-height: normal;" class=""><span style="font-size: 14px;" class="">Alas, commenting that out still gives an error when writing the .idx, but now on an index SUBitem (new log file attached).</span></div><div style="margin: 0px; font-stretch: normal; font-size: 18px; line-height: normal;" class=""><span style="font-size: 14px;" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class="">Here’s my complete .ist, to which the error is conceivably related.</div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">% MakeIndex style file</font></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">% output main entry <entry> as: \item \idxmark{<entry>}, </font></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">item_0 "\n\\item \\idxmark{"</font></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">delim_0 "}, "</font></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">% not forgetting the subitem case</font></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">item_x1 "} \n \\subitem "</font></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">headings_flag 1</font></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">heading_prefix "{\\medskip\\hfill\\large\\textsf{\\textbf{"</font></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">heading_suffix "}}\\hfill}\\medskip\\nopagebreak\n”</font></div><div style="margin: 0px; font-stretch: normal; font-size: 18px; line-height: normal;" class=""><br class=""></div></div><div>Recall from my original messge that \idxmark is defined by:</div><div><br class=""></div><div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">\newcommand{\idxmark}[1]{{\let\gobbleone\relax\markboth{\sffamily\bfseries#1}{\sffamily\bfseries#1}}#1}</font></div><div class=""><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><font face="Courier" class="">\providecommand\gobbleone[1]{}</font></div></div><div style="margin: 0px; font-stretch: normal; font-size: 18px; line-height: normal;" class=""><br class=""></div></div><div>I did manually go through the entire ..ind file to see if I could find an unmatched “$” in entries there, but I did not. Can any wizard with regex knowledge check that, too? So I’ve also attached the .ind file.</div><div><br class=""></div><div>Murray</div><div></div></div></body></html>