diff --git a/help/info/BNF.html b/help/info/BNF.html
index 6a56b14923c0834eb8b6a914cf42e68a934ff56d..1a3eebea9ecd8c480a0a174f473d8fa1e74fea15 100644
--- a/help/info/BNF.html
+++ b/help/info/BNF.html
@@ -877,7 +877,7 @@ This ABNF browser was generated from file <mockup_bnf.txt> on Tue Jul 20 1
<TD>
<P><A NAME="componentdef"></a><A HREF="#Xref.ComponentDef">ComponentDef</A>
<TD VALIGN=TOP>=</TD>
- <TD><A HREF="#componentkeyword">ComponentKeyword</A> <A HREF="#componenttypeidentifier">ComponentTypeIdentifier</A> <A HREF="#beginchar">BeginChar</A> [<A HREF="#componentdeflist">ComponentDefList</A>]
+ <TD><A HREF="#componentkeyword">ComponentKeyword</A> <A HREF="#componenttypeidentifier">ComponentTypeIdentifier</A> [<A HREF="#extendskeyword">ExtendsKeyword</A> <A HREF="#componenttypeidentifier">ComponentTypeIdentifier</A>] <A HREF="#beginchar">BeginChar</A> [<A HREF="#componentdeflist">ComponentDefList</A>]
<A HREF="#endchar">EndChar</A></TD>
</TR>
<TR VALIGN=TOP>
@@ -894,6 +894,16 @@ This ABNF browser was generated from file <mockup_bnf.txt> on Tue Jul 20 1
<TD></TD>
<TD></TD>
</TR>
+ <TR VALIGN=TOP>
+ <TD>
+ <P><A NAME="extendskeyword"></a><A HREF="#Xref.ExtendsKeyword">ExtendsKeyword</A>
+ <TD VALIGN=TOP>=</TD>
+ <TD>"<FONT COLOR="black">extends</FONT>"</TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD></TD>
+ <TD></TD>
+ </TR>
<TR VALIGN=TOP>
<TD>
<P><A NAME="componenttype"></a><A HREF="#Xref.ComponentType">ComponentType</A>
@@ -5766,6 +5776,10 @@ This ABNF browser was generated from file <mockup_bnf.txt> on Tue Jul 20 1
<TD><A NAME="Xref.ExtendedFieldReference"></a><A HREF="#extendedfieldreference">ExtendedFieldReference</A></TD>
<TD><A HREF="#variableref">VariableRef</A>, <A HREF="#referencedtype">ReferencedType</A>, <A HREF="#referencedvalue">ReferencedValue</A></TD>
</TR>
+ <TR VALIGN=TOP>
+ <TD><A NAME="Xref.ExtendsKeyword"></a><A HREF="#extendskeyword">ExtendsKeyword</A></TD>
+ <TD><A HREF="#componentdef">ComponentDef</A></TD>
+ </TR>
<TR VALIGN=TOP>
<TD><A NAME="Xref.ExtensionKeyword"></a><A HREF="#extensionkeyword">ExtensionKeyword</A></TD>
<TD><A HREF="#attribkeyword">AttribKeyword</A></TD>
diff --git a/help/info/component.html b/help/info/component.html
index 994ec98cf8d547495d199cd835112187fee8985c..4d6c27b6587f90633d60e477b98cf4a8ba88cd35 100644
--- a/help/info/component.html
+++ b/help/info/component.html
@@ -46,6 +46,7 @@
<p>Related keywords:</p>
<ul>
<li><a href="type.html"><b><font face="Courier New" color="#003258" size="4">type</font></b></a></li>
+ <li><a href="extends.html"><b><font face="Courier New" color="#003258" size="4">extends</font></b></a></li>
<li><a href="port.html"><b><font face="Courier New" color="#003258" size="4">port</font></b></a></li>
<li><a href="const.html"><b><font face="Courier New" color="#003258" size="4">const</font></b></a></li>
<li><a href="var.html"><b><font face="Courier New" color="#003258" size="4">var</font></b></a></li>
diff --git a/help/info/extends.html b/help/info/extends.html
new file mode 100644
index 0000000000000000000000000000000000000000..68856f9d5fab436e1f9b5a1235e7cf85b6c266a5
--- /dev/null
+++ b/help/info/extends.html
@@ -0,0 +1,105 @@
+<!--
+ Copyright (c) 2000-2020 Ericsson Telecom AB
+ All rights reserved. This program and the accompanying materials
+ are made available under the terms of the Eclipse Public License v2.0
+ which accompanies this distribution, and is available at
+ https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html
+
+ Contributors:
+ Baji, Laszlo
+ Balasko, Jeno
+ Farkas, Laszlo
+ Szabados, Kristof
+ Lenard, Nagy
+-->
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+<meta http-equiv="Content-Language" content="en-us">
+<title>extends</title>
+</head>
+<body bgcolor="#DAD3C5" vlink="#0094D2" link="#003258">
+<table align="left" border="0" cellspacing="0" cellpadding="0" valign=top>
+ <tr>
+ <td width=105 height=40><a href="https://projects.eclipse.org/projects/tools.titan"><img src="../images/titan_transparent.gif" border=0 width=105 height=40 align="left" alt="Titan"></a></td>
+ </tr>
+</table>
+<table border="0" align="right" cellpadding="0" cellspacing="0">
+ <tr>
+ <td><a href="../titan_main.html" alt="contents"><img border="0" src="../images/ao.jpg" width="53" height="40"></a></td>
+ <td><a href="../titan_index.html" alt="index"><img border="0" src="../images/up.jpg" width="53" height="40"></a></td>
+ <td><a href="complement.html" alt="previous"><img border="0" src="../images/left.jpg" width="53" height="40"></a></td>
+ <td><a href="connect.html" alt="next"><img border="0" src="../images/right.jpg" width="53" height="40"></a></td>
+ </tr>
+</table>
+<p><br clear="all">
+</p>
+<hr>
+<h1>extends</h1>
+<hr align="left" width="75%">
+<p>The keyword is used to specify the parent component type on which the new component type is based.</p>
+<p>In such a definition, the new type definition is referred to as the extended type, and the type definition following the
+ extends keyword is referred to as the parent type. The effect of this definition is that the extended type will implicitly
+ also contain all definitions from the parent type. It is called the effective type definition.</p>
+<p> It is allowed to have one component type extending several parent types in one definition, which have to be specified as
+ a comma-separated list of types in the definition. Any of the parent types may also be defined by means of extension.
+ The effective component type definition of the extended type is obtained as the collection of all constant, variable,
+ template, timer and port definitions contributed by the parent types (determined recursively if a parent type is also
+ defined by means of an extension) and the definitions declared in the extended type directly. The effective component
+ type definition shall be name clash free.</p>
+<p>Related keywords:</p>
+<ul>
+ <li><a href="type.html"><b><font face="Courier New" color="#003258" size="4">type</font></b></a></li>
+ <li><a href="component.html"><b><font face="Courier New" color="#003258" size="4">component</font></b></a></li>
+</ul>
+<hr align="left" width="50%">
+<div align="center">
+<center>
+<table border="0" width="90%" bgcolor="#FFB599" cellpadding="4">
+ <tr>
+ <td width="100%">
+ <h3 align="center"><font face="Courier New" color="#003258" size="5"><b>type component </b></font> <i>component_identifier </i> <font face="Courier New" color="#003258" size="5"><b>extends</b></font> <i>parent_component_type_identifier</i> <font face="Courier New" color="#003258" size="5"><b>{</b></font>
+ [ <i>port_instance</i><font face="Courier New" color="#003258" size="5"><b>;</b></font> ] [ <i>const_def</i><font face="Courier New" color="#003258" size="5"><b>;</b></font> ] [ <i>var_instance</i><font
+ face="Courier New" color="#003258" size="5"><b>;</b></font> ] [ <i>timer_instance</i><font face="Courier New" color="#003258" size="5"><b>;</b></font> ] <font face="Courier New"
+ color="#003258" size="5"><b>};</b></font></h3>
+ </td>
+ </tr>
+</table>
+</center>
+</div>
+<ul>
+ <li>
+ <p>The <i>parent_component_type_identifier</i> specifies the component type to be extended</p>
+ </li>
+</ul>
+<p></p>
+<hr align="left" width="50%">
+<p>Example 1:
+<p><font face="Courier New">type component MyParentComponentType_CT {<br>
+ port MyMessagePortType_PT P1_PCO;<br>
+ const bitstring c_MyConst := ’1001’B; <br>
+ var integer v_MyVar; <br>
+ timer T_MyTimer := 1.0; <br>
+}
+</p>
+
+<p><font face="Courier New">type component MyExtendedComponentType_CT extends MyParentComponentType_CT {<br>
+ port MyOtherMessagePortType_PT P2_PCO;<br>
+ const bitstring c_MyOtherConst := ’0110’B; <br>
+ var integer v_MyOtherVar; <br>
+ timer T_MyOtherTimer := 2.0; <br>
+ }
+</p>
+
+
+</font>
+<p>The component called MyExtendedComponentType_CT is declared by extending MyParentComponentType_CT. <br>
+The resulting extended component contains two ports (P1_PCO,P2_PCO) of type MyMessagePortType_PT, <br>
+two constants called c_MyConst and c_MyOtherConst, <br>
+two variables called v_MyVar and v_MyOtherVar <br>
+and two timers called T_MyTimer and T_MyOtherTimer.</p>
+<hr align="left" width="25%">
+<hr align="left" width="25%">
+<p><a HREF="BNF.html#componentdef">BNF definition</a> of <font face="Courier New"> extends</font></p>
+</body>
+</html>