#This file was created by <larsbj> Sun Dec  5 17:47:02 1999
#LyX 1.0 (C) 1995-1999 Matthias Ettrich and the LyX Team
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\language english
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\layout Title

User defined macros in math mode
\layout Author

Alejandro Aguilar Sierra
\layout Date

25-October-1997
\layout Section

Introduction
\layout Standard

LyX version 0.12 allows the user to define macros.
 An user defined macro in math mode is not a red colored name that LyX didn't
 know how to draw (formerly known as macro mode, now simply TeX mode).
 A macro definition box appears on screen as a grayed button with the name
 of the macro in blue (math color).
 But if you click on it, it will appear as a normal math box to allow you
 edit it.
 Just try it:
\begin_inset FormulaMacro 
\newcommand{\macro}{a+b}

\end_inset 


\layout Standard

Now, to use this macro in other math boxes just type the name in TeX mode,
 in this case 
\family typewriter 

\backslash 
macro
\family default 
, and it will be automatically expanded: 
\begin_inset Formula \( c=\macro  \)
\end_inset 

.
 As you can verify, the cursor can't go inside the macro, the whole macro
 is like a single character, and the TeX generated code of this expression
 is 
\family typewriter 
c = 
\backslash 
macro.
\layout Standard

However the cursor could go inside of some kind of macros, those that have
 
\emph on 
arguments
\emph default 
.
 In a macro definition box an argument looks like a 
\family typewriter 
#
\family default 
 followed by the argument number:
\begin_inset FormulaMacro 
\newcommand{\macrowarg}[1]{2+\sqrt{#1 }}

\end_inset 


\layout Standard

Once expanded, this macro includes the usual empty rectangle to indicate
 that you can insert there whatever you want: 
\family typewriter 

\backslash 
macrowarg = 
\begin_inset Formula \( \macrowarg{} \)
\end_inset 


\family default 
.
 Example: 
\begin_inset Formula \( b=\macrowarg{x-2} \)
\end_inset 

.
 
\layout Standard

When exported to LaTeX, a macro definition will produce the command 
\family typewriter 

\backslash 
newcommand.
\layout Section

Directions on using macros
\layout Subsection

How to create them
\layout Standard

To create a macro definition box use this syntax in the minibuffer:
\layout Standard


\family typewriter 
math-macro <macro name> [number of arguments]
\layout Standard

Par example 
\family typewriter 

\backslash 
macro
\family default 
 was created with 
\begin_inset Quotes eld
\end_inset 


\family typewriter 
math-macro macro
\family default 

\begin_inset Quotes erd
\end_inset 

, and 
\family typewriter 

\backslash 
macrowarg
\family default 
 was created with 
\begin_inset Quotes eld
\end_inset 


\family typewriter 
math-macro macrowarg 1
\family default 

\begin_inset Quotes erd
\end_inset 

.
\layout Standard

To insert an argument mark (only inside a macro definition box) use this:
\layout Standard


\family typewriter 
math-macro-arg <number>
\layout Standard

The argument mark in 
\family typewriter 

\backslash 
macrowarg
\family default 
 was introduced with 
\begin_inset Quotes eld
\end_inset 


\family typewriter 
math-macro-arg 1
\family default 

\begin_inset Quotes erd
\end_inset 

.
\layout Standard

You can use no more than 9 arguments, numbered from 1 to 9.
 An argument can be repeated inside the macro definition box, but of course
 can be edited only once.
 A number can't be greater than the number of arguments originally allowed
 for the macro.
 
\layout Subsection

How to navigate
\layout Description

With
\protected_separator 
the
\protected_separator 
arrow
\protected_separator 
keys: Opening a macro form the left side will put the cursor in the first
 argument, to move to the second argument use the TAB key.
 Remember that pressing the Space bar will get the cursor out and at the
 right side of the macro.
\layout Description

With
\protected_separator 
the
\protected_separator 
mouse: As usual, click on the desired argument box.
 Sometimes this fails if the box is empty or too small.
\layout Standard

Currently the user can only define command macros, but internally it's possible
 to define also environment macros.
\layout Standard

There are several predefined macros, mainly to allow AMS-LaTeX users to
 use AMS macros in a WYSIWYM way, like 
\family typewriter 

\backslash 
cases
\family default 
 and 
\family typewriter 

\backslash 
binom
\family default 
.
 [
\emph on 
Pre 0.12 Note: 
\family typewriter 

\backslash 
cases
\family default 
 are currently disabled because after some simplification and improving
 of the macro stuff, the only valid arguments are subparagraphs (neither
 tabs nor newlines).
 Perhaps they will be again included before 0.12
\emph default 
.
 AAS]
\the_end
