diff --git a/Doc/Sd1/LanguageFundamentals/languageFundamentals.xml b/Doc/Sd1/LanguageFundamentals/languageFundamentals.xml
index 1027170756bef104679f98b63eafe86aac0f16c2..5d5b286175596a463054caa014372041a593d8e6 100644
--- a/Doc/Sd1/LanguageFundamentals/languageFundamentals.xml
+++ b/Doc/Sd1/LanguageFundamentals/languageFundamentals.xml
@@ -5720,9 +5720,35 @@ System.out.println(2147483647 + 1L);</programlisting>
               result and propose a solution.</para>
 
               <tip>
-                <para>You will have to replace the <quote>==</quote> operator
-                by something more appropriate addressing limited arithmetic
-                precision.</para>
+                <itemizedlist>
+                  <listitem>
+                    <para>You will have to relax the exact <quote>==</quote>
+                    operator by a »being close to each other« relation
+                    addressing the limited arithmetic precision.</para>
+                  </listitem>
+
+                  <listitem>
+                    <para>The <methodname
+                    xlink:href="https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/Math.html#abs(double)">Math.abs()</methodname>
+                    method calculates the absolute value:</para>
+
+                    <informaltable border="1">
+                      <tr>
+                        <th>Code</th>
+
+                        <th>Result</th>
+                      </tr>
+
+                      <tr>
+                        <td valign="top"><programlisting language="java">System.out.println(Math.abs(10.7));
+System.out.println(Math.abs(-10.7));</programlisting></td>
+
+                        <td valign="top"><screen>10.7
+10.7</screen></td>
+                      </tr>
+                    </informaltable>
+                  </listitem>
+                </itemizedlist>
               </tip>
             </question>