Per triplo indice intendo un indice che metta in evidenza il capitolo, la sezione e il numero della formula; qualcosa tipo (1.2.3). Poichè non mi piaceva ho inserito i comandi \numberwithin per chiedere di non esibire il secondo numero, relativo alla sezione.
Qui sotto copio e incollo le mie impostazioni, dove si vede come uso questo comando.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\documentclass[11pt,leqno]{book}
\usepackage{amssymb,amsmath,amsthm}
\usepackage{color}
%\pagestyle{empty}
%\usepackage[dvips]{color}
%\usepackage{multicol}
\oddsidemargin=0.5cm \evensidemargin=0.6cm \textwidth=14.8cm
\textheight=22.8cm \topmargin=-0.5cm
\def\th{\vartheta}
\newcommand{\N}{{\mathbb N}}
\newcommand{\Z}{{\mathbb Z}}
\newcommand{\R}{{\mathbb R}}
\newcommand{\I}{{\mathbb I}}
%\newcommand{\e}{\varepsilon}
\newcommand{\eps}{\varepsilon}
\newcommand{\da}{\omega}
\newcommand{\dist}{{\rm dist}}
\newcommand{\Frac}{{\rm dim}_{\rm F}\,}
\def \bra#1{\langle #1 \rangle}
\newcommand{\F}{{\mathcal F}}
\newcommand{\A}{{\mathcal A}}
\newcommand{\B}{{\mathcal B}}
\newcommand{\C}{{\mathcal C}}
\newcommand{\D}{{\mathcal D}}
\newcommand{\E}{{\mathcal E}}
\newcommand{\G}{{\mathcal G}}
\newcommand{\LS}{{\L}}
%\def\m {{\L}}
\def\L {{\mathcal L}}
\newcommand{\M}{{\mathcal M}}
\newcommand{\Q}{{\mathcal Q}}
\newcommand{\Ze}{{\mathcal Z}}
\renewcommand{\P}{{\mathcal P}}
\newcommand{\K}{{\mathcal K}}
\newcommand{\h}{{\rm H}}
\def\H {{\mathcal H}}
\def\T {{\mathcal T}}
\def\V {{\mathcal V}}
\def\W {{\mathcal W}}
\def\X {{\mathcal X}}
\def\Y {{\mathcal Y}}
\def\ll {\langle\!\langle}
\def\rr {\rangle\!\rangle}
\def\au{\rm}
\def\ti{\em}
\def\jou{\rm}
\def\bk{\noveit}
\def\no#1#2#3 {{\bf #1}, {\rm #2} {\rm (#3)}}
\def\eds#1#2#3 {{\rm #1}, {\rm #2} {\rm (#3)}}
\def \bk {\it}
\def \l {\langle}
\def \r {\rangle}
\newcommand{\weak}{\stackrel{_w}{\to}}
\newcommand{\wstar}{\stackrel{_{w^*}}{\to}}
\newtheorem*{probae}{Problem $\boldsymbol{P_{\ace}}$}
\newtheorem{theorem}{Theorem}[chapter]
\newtheorem{proposition}[theorem]{Proposition}
\newtheorem{corollary}[theorem]{Corollary}
\newtheorem{lemma}[theorem]{Lemma}
%\theoremstyle{definition}
\newtheorem{definition}[theorem]{Definition}
\newtheorem{remark}[theorem]{Remark}
%\newenvironment{proof}{{\bf Proof}}%[proof]
\newcommand{\ball}[2]{{\rm B}_{#2}\left(#1\right)}
\newcommand{\dint}{\displaystyle \int}
\newcommand{\ps}[2]{\langle {#1},{#2} \rangle}
\newcommand{\psh}[2]{\langle {#1},{#2} \rangle _H}
\newcommand{\norml}[1]{{\Vert {#1} \Vert}_H}
\newcommand{\normv}[1]{{\Vert {#1} \Vert}_V}
\newcommand{\norm}[1]{\Vert {#1} \Vert}
\numberwithin{equation}{chapter}
\numberwithin{theorem}{chapter}
%%%%%%%%%%%%%%%[comandi speciali]%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\definecolor{giallo}{rgb}{1,0.7,0}
\definecolor{verdone}{rgb}{0,0.5,0.2}
\definecolor{arancione}{rgb}{1,0.35,0}
\newcommand{\ac}{\alpha}
%\newcommand{\ac}{{\color{red}\alpha}}
\newcommand{\ec}{\varepsilon}
%\newcommand{\ec}{{\color{giallo}\varepsilon}}
\newcommand{\bc}{\beta}
%\newcommand{\bc}{{\color{blue}\beta}}
\newcommand{\lc}{\lambda}
%\newcommand{\lc}{{\color{magenta}\lambda}}
\newcommand{\rc}{\rho}
%\newcommand{\rc}{{\color{green}\rho}}
\newcommand{\nc}{\nu}
%\newcommand{\nc}{{\color{verdone}\nu}}
\newcommand{\si}{\sigma}
%\newcommand{\si}{{\color{arancione}\sigma}}
\newcommand{\ga}{\gamma}
%\newcommand{\ga}{{\color{arancione}\gamma}}
\newcommand{\kc}{\sigma}
%\newcommand{\kc}{{\color{arancione}\sigma}}
%\newcommand{\ace}{\ec}
\newcommand{\ace}{\ac,\ec}
%\newcommand{\ea}{\ace}
\newcommand{\ea}{\ec}
%\newcommand{\Q1}{\Q}
%\newcommand{\Q1}{\Q(\ec_1)}
\newcommand{\ecq}{[0,\ec_1]}
\newcommand{\ev}{e}
\newcommand{\tc}{\vartheta}%^{(\ac,\ec)}
\newcommand{\tct}{\vartheta(t)}%^{(\ac,\ec)}
\newcommand{\cc}{\chi}%^{(\ac,\ec)}
\newcommand{\cct}{\chi(t)}%^{(\ac,\ec)}
\newcommand{\e}{\eta}%^{(\ac,\ec)}
\newcommand{\et}{\eta^t}%^{(\ac,\ec)}
%\newcommand{\ez}{\eta^{(\ac,\ec),0}}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Alcunedefinizioni (o ridefinizioni) sono di comodo, e non le ho usate.
Ho provato a compilare da solo in capitolo 11, e mi fa lo stesso scherzetto. Probabilmente il problema sta lì, ma non riesco a trovarlo. Escluderei che esso sia relativo ai label, poichè ho provato a cambiarne qualcuno ma la situazione non cambia.
GLM