diff --git a/lib/doc/Math.lyx b/lib/doc/Math.lyx
index 17d425b7e9..f8e632c3e7 100644
--- a/lib/doc/Math.lyx
+++ b/lib/doc/Math.lyx
@@ -91,11 +91,6 @@
 % example macro from sec. 19.4
 %\def\tagform@#1{\maketag@@@{|#1|}}
 
-% macro from sec. 10.2
-\def\clap#1{\hbox to 0pt{\hss #1\hss}}
-\def\mathclap {\mathpalette \mathclapinternal}
-\def\mathclapinternal #1#2{\clap{$\mathsurround =0pt #1{#2}$}}
-
 
 % ------------------------------------
 % used to check for needed LaTeX packages
@@ -185,7 +180,7 @@
 \use_package cancel 0
 \use_package esint 1
 \use_package mathdots 1
-\use_package mathtools 0
+\use_package mathtools 1
 \use_package mhchem 1
 \use_package stackrel 0
 \use_package stmaryrd 0
@@ -291,7 +286,7 @@ status open
 \begin_layout Plain Layout
 To export this document to PDF, PS or DVI the LaTeX-packages 
 \series bold
-braket, cancel, eurosym, mathdots, mhchem, undertilde
+braket, cancel, eurosym, mathdots, mathtools, mhchem, undertilde
 \series default
  and 
 \series bold
@@ -15582,54 +15577,7 @@ reference "eq:substack"
 
  there can be too much space beside an operator, because the characters
  following the operator are set beside the limits.
-\end_layout
-
-\begin_layout Standard
-To avoid this, the following macro can be used in the LaTeX-preamble:
-\end_layout
-
-\begin_layout Standard
-
-\series bold
-
-\backslash
-def
-\backslash
-clap#1{
-\backslash
-hbox to 0pt{
-\backslash
-hss #1
-\backslash
-hss}}
-\begin_inset Newline newline
-\end_inset
-
-
-\backslash
-def
-\backslash
-mathclap {
-\backslash
-mathpalette 
-\backslash
-mathclapinternal}
-\begin_inset Newline newline
-\end_inset
-
-
-\backslash
-def
-\backslash
-mathclapinternal #1#2{
-\backslash
-clap{$
-\backslash
-mathsurround =0pt #1{#2}$}}
-\end_layout
-
-\begin_layout Standard
-This defines the command 
+ To avoid this the command 
 \series bold
 
 \backslash
@@ -15647,27 +15595,15 @@ mathclap
 
 \end_inset
 
- that sets the width of the limit to 0
+ can be used.
+ It sets the width of its content to 0
 \begin_inset space \thinspace{}
 \end_inset
 
 pt.
- The command scheme is
-\end_layout
+\begin_inset Newline newline
+\end_inset
 
-\begin_layout Standard
-
-\series bold
-
-\backslash
-mathclap{limit}
-\end_layout
-
-\begin_layout Standard
-where the limit can consist of several conditions.
-\end_layout
-
-\begin_layout Standard
 Applied on formula 
 \begin_inset CommandInset ref
 LatexCommand eqref
@@ -15685,7 +15621,7 @@ reference "eq:substack"
 \backslash
 sum_
 \backslash
-mathclap{
+mathclap
 \backslash
 substack
 \begin_inset space \textvisiblespace{}
diff --git a/lib/doc/de/Math.lyx b/lib/doc/de/Math.lyx
index 870d75d2f8..a3884775dc 100644
--- a/lib/doc/de/Math.lyx
+++ b/lib/doc/de/Math.lyx
@@ -92,16 +92,12 @@
 % Beispielmakro aus Kap. 19.4
 %\def\tagform@#1{\maketag@@@{|#1|}}
 
-% Makro aus Kap. 10.2
-\def\clap#1{\hbox to 0pt{\hss #1\hss}}
-\def\mathclap {\mathpalette \mathclapinternal}
-\def\mathclapinternal #1#2{\clap{$\mathsurround =0pt #1{#2}$}}
-
 % Damit der Index einen anderen Namen erhält.
 \addto\captionsngerman
 {\renewcommand{\indexname}
 {Stichwort- und Befehlsverzeichnis}}
 
+
 % ------------------------------------
 % used to check for needed LaTeX packages
 \usepackage{ifthen}
@@ -194,7 +190,7 @@
 \use_package cancel 0
 \use_package esint 1
 \use_package mathdots 1
-\use_package mathtools 0
+\use_package mathtools 1
 \use_package mhchem 1
 \use_package stackrel 0
 \use_package stmaryrd 0
@@ -300,7 +296,7 @@ status open
 Um diese Datei als PDF, PS oder DVI zu exportieren, sollten die LaTeX-Pakete
  
 \series bold
-braket, cancel, eurosym, mathdots, mhchem, undertilde
+braket, cancel, eurosym, mathdots, mathtools, mhchem, undertilde
 \series default
  und 
 \series bold
@@ -15595,54 +15591,7 @@ reference "eq:substack"
 
  kann es vorkommen, dass sich neben dem Operator zu viel Leerraum befindet,
  denn das dem Operator folgende Zeichen wird neben die Grenzen gesetzt.
-\end_layout
-
-\begin_layout Standard
-Um das zu verhindern, kann man folgendes Makro in den LaTeX-Vorspann einfügen:
-\end_layout
-
-\begin_layout Standard
-
-\series bold
-
-\backslash
-def
-\backslash
-clap#1{
-\backslash
-hbox to 0pt{
-\backslash
-hss #1
-\backslash
-hss}}
-\begin_inset Newline newline
-\end_inset
-
-
-\backslash
-def
-\backslash
-mathclap {
-\backslash
-mathpalette 
-\backslash
-mathclapinternal}
-\begin_inset Newline newline
-\end_inset
-
-
-\backslash
-def
-\backslash
-mathclapinternal #1#2{
-\backslash
-clap{$
-\backslash
-mathsurround =0pt #1{#2}$}}
-\end_layout
-
-\begin_layout Standard
-Dadurch wird der Befehl 
+ Um das zu verhindern, kann man den Befehl 
 \series bold
 
 \backslash
@@ -15660,27 +15609,14 @@ mathclap
 
 \end_inset
 
- definiert, der die Breite der Grenze auf 0
+ verwenden, der die Breite seines Inhalts auf 0
 \begin_inset space \thinspace{}
 \end_inset
 
 pt setzt.
- Das Befehlsschema lautet
-\end_layout
+\begin_inset Newline newline
+\end_inset
 
-\begin_layout Standard
-
-\series bold
-
-\backslash
-mathclap{Grenze}
-\end_layout
-
-\begin_layout Standard
-wobei die Grenze auch aus mehreren Bedingungen bestehen kann.
-\end_layout
-
-\begin_layout Standard
 Auf Formel 
 \begin_inset CommandInset ref
 LatexCommand eqref
@@ -15688,7 +15624,7 @@ reference "eq:substack"
 
 \end_inset
 
- angewandt, gibt man also den Befehl
+ angewandt, gibt man den Befehl
 \end_layout
 
 \begin_layout Standard
@@ -15698,7 +15634,7 @@ reference "eq:substack"
 \backslash
 sum_
 \backslash
-mathclap{
+mathclap
 \backslash
 substack
 \begin_inset space \textvisiblespace{}
diff --git a/lib/doc/es/Math.lyx b/lib/doc/es/Math.lyx
index f34395507a..b17fee8ccc 100644
--- a/lib/doc/es/Math.lyx
+++ b/lib/doc/es/Math.lyx
@@ -92,11 +92,6 @@
 % example macro from sec. 19.4
 %\def\tagform@#1{\maketag@@@{|#1|}}
 
-% macro from sec. 10.2
-\def\clap#1{\hbox to 0pt{\hss #1\hss}}
-\def\mathclap {\mathpalette \mathclapinternal}
-\def\mathclapinternal #1#2{\clap{$\mathsurround =0pt #1{#2}$}}
-
 
 % ------------------------------------
 % used to check for needed LaTeX packages
@@ -186,7 +181,7 @@
 \use_package cancel 0
 \use_package esint 1
 \use_package mathdots 1
-\use_package mathtools 0
+\use_package mathtools 1
 \use_package mhchem 1
 \use_package stackrel 0
 \use_package stmaryrd 0
@@ -293,7 +288,7 @@ status open
 Para exportar este documento a PDF, PS o DVI deberían estar instalados los
  paquetes LaTeX 
 \series bold
-braket, cancel, eurosym, mathdots, mhchem, undertilde
+braket, cancel, eurosym, mathdots, mathtools, mhchem, undertilde
 \series default
  y 
 \series bold
@@ -15655,54 +15650,7 @@ reference "eq:substack"
 \end_inset
 
 , porque éstos se colocan junto a los límites.
-\end_layout
-
-\begin_layout Standard
-Para evitarlo se puede usar la siguiente macro en el preámbulo:
-\end_layout
-
-\begin_layout Standard
-
-\series bold
-
-\backslash
-def
-\backslash
-clap#1{
-\backslash
-hbox to 0pt{
-\backslash
-hss #1
-\backslash
-hss}}
-\begin_inset Newline newline
-\end_inset
-
-
-\backslash
-def
-\backslash
-mathclap {
-\backslash
-mathpalette 
-\backslash
-mathclapinternal}
-\begin_inset Newline newline
-\end_inset
-
-
-\backslash
-def
-\backslash
-mathclapinternal #1#2{
-\backslash
-clap{$
-\backslash
-mathsurround =0pt #1{#2}$}}
-\end_layout
-
-\begin_layout Standard
-En ella se define el comando 
+ Para evitarlo se puede usar comando 
 \series bold
 
 \backslash
@@ -15720,27 +15668,18 @@ mathclap
 
 \end_inset
 
- que establece la anchura del límite en 0
+ que 
+\lang english
+sets the width of its content to
+\lang spanish
+ 0
 \begin_inset space \thinspace{}
 \end_inset
 
 pt.
- El esquema del comando es:
-\end_layout
+\begin_inset Newline newline
+\end_inset
 
-\begin_layout Standard
-
-\series bold
-
-\backslash
-mathclap{límite}
-\end_layout
-
-\begin_layout Standard
-donde el límite puede consistir en varias condiciones.
-\end_layout
-
-\begin_layout Standard
 Aplicado en la ecuación 
 \begin_inset CommandInset ref
 LatexCommand eqref
@@ -15758,7 +15697,7 @@ reference "eq:substack"
 \backslash
 sum_
 \backslash
-mathclap{
+mathclap
 \backslash
 substack
 \begin_inset space \textvisiblespace{}
diff --git a/lib/doc/fr/Math.lyx b/lib/doc/fr/Math.lyx
index b33f3e2b38..2c02c691ff 100644
--- a/lib/doc/fr/Math.lyx
+++ b/lib/doc/fr/Math.lyx
@@ -92,11 +92,6 @@
 % example macro from sec. 19.4
 %\def\tagform@#1{\maketag@@@{|#1|}}
 
-% macro from sec. 10.2
-\def\clap#1{\hbox to 0pt{\hss #1\hss}}
-\def\mathclap {\mathpalette \mathclapinternal}
-\def\mathclapinternal #1#2{\clap{$\mathsurround =0pt #1{#2}$}}
-
 
 % ------------------------------------
 % used to check for needed LaTeX packages
@@ -189,7 +184,7 @@
 \use_package cancel 0
 \use_package esint 1
 \use_package mathdots 1
-\use_package mathtools 0
+\use_package mathtools 1
 \use_package mhchem 1
 \use_package stackrel 0
 \use_package stmaryrd 0
@@ -306,7 +301,7 @@ status open
 Pour pouvoir exporter ce document en PDF, PS, ou DVI les paquetages LaTeX
  
 \series bold
-braket, cancel, eurosym, mathdots, mhchem, undertilde
+braket, cancel, eurosym, mathdots, mathtools, mhchem, undertilde
 \series default
  et 
 \series bold
@@ -15167,13 +15162,6 @@ dotsint
 \end_inset
 
 
-\end_layout
-
-\begin_layout Standard
-\begin_inset Newpage newpage
-\end_inset
-
-
 \end_layout
 
 \begin_layout Subsection
@@ -15580,54 +15568,7 @@ reference "eq:substack"
 
 , il se peut qu'il y ait trop d'espace après un opérateur, puisque les caractère
 s qui suivent l'opérateur se trouvent après la limite.
-\end_layout
-
-\begin_layout Standard
-Pour éviter cela, on peut utiliser la macro suivante dans le préambule LaTeX:
-\end_layout
-
-\begin_layout Standard
-
-\series bold
-
-\backslash
-def
-\backslash
-clap#1{
-\backslash
-hbox to 0pt{
-\backslash
-hss #1
-\backslash
-hss}}
-\begin_inset Newline newline
-\end_inset
-
-
-\backslash
-def
-\backslash
-mathclap {
-\backslash
-mathpalette 
-\backslash
-mathclapinternal}
-\begin_inset Newline newline
-\end_inset
-
-
-\backslash
-def
-\backslash
-mathclapinternal #1#2{
-\backslash
-clap{$
-\backslash
-mathsurround =0pt #1{#2}$}}
-\end_layout
-
-\begin_layout Standard
-Elle définit la commande 
+ Pour éviter cela, on peut utiliser la commande 
 \series bold
 
 \backslash
@@ -15645,27 +15586,18 @@ mathclap
 
 \end_inset
 
- qui met la largeur de la limite à 0
+ qui met la largeur 
+\lang english
+of its content
+\lang french
+ à 0
 \begin_inset space \thinspace{}
 \end_inset
 
 pt.
- La syntaxe de la commande est:
-\end_layout
+\begin_inset Newline newline
+\end_inset
 
-\begin_layout Standard
-
-\series bold
-
-\backslash
-mathclap{limite}
-\end_layout
-
-\begin_layout Standard
-où la limite peut être composée de plusieurs conditions.
-\end_layout
-
-\begin_layout Standard
 Appliqué à la formule 
 \begin_inset CommandInset ref
 LatexCommand eqref
@@ -15683,7 +15615,7 @@ reference "eq:substack"
 \backslash
 sum_
 \backslash
-mathclap{
+mathclap
 \backslash
 substack
 \begin_inset space \textvisiblespace{}
diff --git a/lib/doc/ja/Math.lyx b/lib/doc/ja/Math.lyx
index 70ba865822..d325c6162a 100644
--- a/lib/doc/ja/Math.lyx
+++ b/lib/doc/ja/Math.lyx
@@ -100,11 +100,6 @@
 % example macro from sec. 19.4
 %\def\tagform@#1{\maketag@@@{|#1|}}
 
-% macro from sec. 10.2
-\def\clap#1{\hbox to 0pt{\hss #1\hss}}
-\def\mathclap {\mathpalette \mathclapinternal}
-\def\mathclapinternal #1#2{\clap{$\mathsurround =0pt #1{#2}$}}
-
 
 % ------------------------------------
 % used to check for needed LaTeX packages
@@ -226,7 +221,7 @@ End
 \use_package cancel 0
 \use_package esint 1
 \use_package mathdots 1
-\use_package mathtools 0
+\use_package mathtools 1
 \use_package mhchem 1
 \use_package stackrel 0
 \use_package stmaryrd 0
@@ -15402,59 +15397,10 @@ reference "eq:substack"
 \end_inset
 
 式のように、演算子の横の余白が大きくなりすぎることがあります。
-\end_layout
-
-\begin_layout Standard
-これを避けるには、LaTeXプリアンブルに以下のようなマクロを指定する方法があります。
-\end_layout
-
-\begin_layout Standard
-
-\series bold
-
-\backslash
-def
-\backslash
-clap#1{
-\backslash
-hbox to 0pt{
-\backslash
-hss #1
-\backslash
-hss}}
-\begin_inset Newline newline
-\end_inset
-
-
-\backslash
-def
-\backslash
-mathclap {
-\backslash
-mathpalette 
-\backslash
-mathclapinternal}
-\begin_inset Newline newline
-\end_inset
-
-
-\backslash
-def
-\backslash
-mathclapinternal #1#2{
-\backslash
-clap{$
-\backslash
-mathsurround =0pt #1{#2}$}}
-\end_layout
-
-\begin_layout Standard
-これは、範囲の幅を0
-\begin_inset space \thinspace{}
-\end_inset
-
-ptに設定する
+\lang english
+To avoid this the command 
 \series bold
+\lang japanese
 
 \backslash
 mathclap
@@ -15471,22 +15417,19 @@ mathclap
 
 \end_inset
 
-コマンドを定義しています。このコマンドの書式は、
-\end_layout
 
-\begin_layout Standard
+\lang english
+ can be used.
+ It sets the width of its content to 0
+\begin_inset space \thinspace{}
+\end_inset
 
-\series bold
+pt.
+\begin_inset Newline newline
+\end_inset
 
-\backslash
-mathclap{範囲}
-\end_layout
 
-\begin_layout Standard
-となっていて、「範囲」には複数の条件を入れることができます。
-\end_layout
-
-\begin_layout Standard
+\lang japanese
 これを
 \begin_inset CommandInset ref
 LatexCommand eqref
@@ -15504,7 +15447,7 @@ reference "eq:substack"
 \backslash
 sum_
 \backslash
-mathclap{
+mathclap
 \backslash
 substack
 \begin_inset space \textvisiblespace{}