diff --git a/doc/manual.xml b/doc/manual.xml
index d44fb0d71ed32f0c8979d0bb2b113de283a0dcce..fe4b7c37b3ac3b6dcc6978055564a8fe87a25a83 100644
--- a/doc/manual.xml
+++ b/doc/manual.xml
@@ -59,6 +59,8 @@ modified versions.
<indexterm zone="rplot"><primary>rplot</primary></indexterm>
<indexterm zone="dynasave"><primary>dynasave</primary></indexterm>
<indexterm zone="dynatype"><primary>dynatype</primary></indexterm>
+<indexterm zone="define"><primary>@define</primary></indexterm>
+<indexterm zone="if_elseif_else_end"><primary>@if...@elseif...@else...@end</primary></indexterm>
</bookinfo>
<preface><title>Preface</title><para>
@@ -99,6 +101,10 @@ Currently the development team of Dynare is composed of S. Adjemian, A. Benzouga
</para>
<section><title>Changes</title>
+<para>December 13, 2005</para>
+<itemizedlist>
+<listitem><para>added conditional compilation commands <xref linkend="define"/> and <xref linkend="if_elseif_else_end"/>.</para></listitem>
+</itemizedlist>
<para>May 3, 2005</para>
<itemizedlist>
<listitem><para>added option <command>noprint</command> in <xref linkend="stoch_simul"/></para></listitem>
@@ -247,7 +253,7 @@ In the description of Dynare commands, the following conventions are observed:
<listitem><para><command><replaceable>INTEGER</replaceable></command> indicates an integer number</para></listitem>
<listitem><para><command><replaceable>DOUBLE</replaceable></command> indicates a double precision number. The following syntaxes are valid: 1.1e3, 1.1E3, 1.1d3, 1.1D3.</para></listitem>
<listitem><para><command><replaceable>EXPRESSION</replaceable></command> indicates a mathematical expression valid in the underlying language (Matlab, Scilab or Gauss)</para></listitem>
-<listitem><para><command><replaceable>VARIABLE_NAME</replaceable></command> indicates a variable name starting with an alphabetical charcater and can't contain ()+-*/^=!;:@#. or accentuated characters</para></listitem>
+<listitem><para><command><replaceable>VARIABLE_NAME</replaceable></command> indicates a variable name starting with an alphabetical character and can't contain ()+-*/^=!;:@#. or accentuated characters</para></listitem>
<listitem><para><command><replaceable>PARAMETER_NAME</replaceable></command> indicates a parameter name starting with an alphabetical charcater and can't contain ()+-*/^=!;:@#. or accentuated characters</para></listitem>
<listitem><para><command><replaceable>FILENAME</replaceable></command> indicates a file name valid under your operating system (Windows, Linux or Unix)</para></listitem>
</itemizedlist>
@@ -257,17 +263,17 @@ In the description of Dynare commands, the following conventions are observed:
<refentry id="Dynare">
<refmeta>
- <refentrytitle>Dynare</refentrytitle>
+ <refentrytitle>dynare</refentrytitle>
</refmeta>
<refnamediv>
- <refname>Dynare</refname>
+ <refname>dynare</refname>
<refpurpose>executes Dynare</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
- <command>Dynare</command>
+ <command>dynare</command>
<arg choice="plain">
<replaceable>FILENAME</replaceable>[.mod]
</arg>
@@ -276,7 +282,7 @@ In the description of Dynare commands, the following conventions are observed:
<refsect1><title>Description</title>
<para>
-<command>Dynare</command> executes instruction included in <filename>filename.mod</filename>.
+<command>dynare</command> executes instruction included in <filename>filename.mod</filename>.
<filename>filename.mod</filename> is the name of the model file containing the
model and the processing instructions.
</para>
@@ -284,7 +290,7 @@ model and the processing instructions.
<refsect1><title>Details</title>
<para>
-In Matlab, <command>Dynare</command> creates three intermediary files:
+In Matlab, <command>dynare</command> creates three intermediary files:
<itemizedlist spacing='compact'>
<listitem><para> <filename>filename.m</filename> with the instructions for the simulations</para></listitem>
<listitem><para> <filename>filename_ff.m</filename> with the dynamic model equations</para></listitem>
@@ -292,7 +298,7 @@ In Matlab, <command>Dynare</command> creates three intermediary files:
</itemizedlist>
</para>
<para>
-In Scilab, <command>Dynare</command> creates three intermediary files:
+In Scilab, <command>dynare</command> creates three intermediary files:
<itemizedlist spacing='compact'>
<listitem><para> <filename>filename.sci</filename> with the instructions for the simulations</para></listitem>
<listitem><para> <filename>filename_ff.sci</filename> with the dynamic model equations</para></listitem>
@@ -300,7 +306,7 @@ In Scilab, <command>Dynare</command> creates three intermediary files:
</itemizedlist>
</para>
<para>
-In Gauss, <command>Dynare</command> creates an intermediary file <filename>filename.gau</filename> with the instructions for the simulations. The Gauss version still accepts the former <filename>.mdl</filename> extension, but it is now deprecated.
+In Gauss, <command>dynare</command> creates an intermediary file <filename>filename.gau</filename> with the instructions for the simulations. The Gauss version still accepts the former <filename>.mdl</filename> extension, but it is now deprecated.
</para>
<para>
These files may be looked at to understand errors reported at the simulation stage.
@@ -309,11 +315,11 @@ These files may be looked at to understand errors reported at the simulation sta
<refsect1><title>Examples</title>
<programlisting>
-Dynare ramst
+dynare ramst
</programlisting>
<para>or</para>
<programlisting>
-Dynare ramst.mod
+dynare ramst.mod
</programlisting>
</refsect1>
</refentry>
@@ -1862,6 +1868,123 @@ In Matlab, variables saved with the <command>dynasave</command> command can be r
</refentry>
</sect1>
+<sect1><title>Conditional compilation</title>
+<para>
+Dynare has the following commands to choose which part of the *.mod file is executed. This is useful to maintain several versions of a model in the same *.mod file.
+</para>
+<itemizedlist>
+<listitem><para><xref linkend='define'/></para></listitem>
+<listitem><para><xref linkend='if_elseif_else_end'/></para></listitem>
+</itemizedlist>
+
+<refentry id="define">
+ <refmeta>
+ <refentrytitle>@define</refentrytitle>
+ </refmeta>
+
+ <refnamediv>
+ <refname>@define</refname>
+ <refpurpose>defines a macro</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <cmdsynopsis>
+ <command>@define</command>
+ <arg choice="plain">
+ <replaceable>VARIABLE_NAME</replaceable>
+ </arg>
+ <arg choice="plain">
+ <replaceable>INTEGER</replaceable>
+ </arg>
+ <arg choice="plain">;</arg>
+ </cmdsynopsis>
+ </refsynopsisdiv>
+<refsect1><title>Description</title>
+<para>
+<command>@define</command> defines a macro with name <replaceable>VARIABLE_NAME</replaceable> and value <replaceable>INTEGER</replaceable>. This macro can be used later in the *.mod file only in <command>@if</command> or <command>@elseif</command> statements. The macros can't be used to replace arbitrary part of codes like in C, for example.
+</para>
+</refsect1>
+
+<refsect1><title>Example</title>
+<para>
+<informalexample>
+<programlisting>
+ @define version 1;
+</programlisting>
+</informalexample>
+</para>
+</refsect1>
+
+</refentry>
+
+<refentry id="if_elseif_else_end">
+ <refmeta>
+ <refentrytitle>@if ... @elseif ... @else ... @end</refentrytitle>
+ </refmeta>
+
+ <refnamediv>
+ <refname>@if ... @elseif ... @else ... @end</refname>
+ <refpurpose>defines conditional compilation of the *.mod file</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <cmdsynopsis>
+ <command>@if</command>
+ <arg choice="plain">
+ <replaceable>VARIABLE_NAME</replaceable>
+ </arg>
+ <arg choice="plain">
+ <replaceable>LOGICAL_OPERATOR</replaceable>
+ </arg>
+ <arg choice="plain">
+ <replaceable>INTEGER</replaceable>
+ </arg>
+ <arg choice="plain">;</arg><sbr/>
+ <arg choice="plain">...</arg><sbr/>
+
+ </cmdsynopsis>
+ </refsynopsisdiv>
+<refsect1><title>Description</title>
+<para><replaceable>LOGICAL_OPERATOR</replaceable> are
+<itemizedlist>
+<listitem><para>== equal</para></listitem>
+<listitem><para>!= not equal</para></listitem>
+<listitem><para>< lesser than</para></listitem>
+<listitem><para>> greater than</para></listitem>
+<listitem><para><= lesser or equal than</para></listitem>
+<listitem><para>>= greater or equal than</para></listitem>
+</itemizedlist>
+</para>
+
+<para>
+These commands let the user define which part of the *.mod file should be handled by Dynare
+</para>
+</refsect1>
+
+<refsect1><title>Example</title>
+<para>
+<informalexample>
+<programlisting>
+ @define version 1;
+ parameters alph bet;
+ alph = 0.3;
+ @if version == 1;
+ bet = 0.9;
+ @elseif version == 2;
+ bet = 0.95;
+ @else;
+ bet = 0.98;
+ @end;
+</programlisting>
+</informalexample>
+</para>
+</refsect1>
+
+</refentry>
+
+</sect1>
+
+
</chapter>
<chapter><title>Examples</title>