Fix the build by syncing language/operators.xml

Author: Sobak

language/operators.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<!-- EN-Revision: 16934048f79c6e117cd16a23c09c1b2ea502e284 Maintainer: sobak Status: ready -->
+<!-- EN-Revision: 2946c8a267734a9e8696e1764f7436e6caa8909c Maintainer: sobak Status: ready -->
 <!-- $Revision$ -->
 <chapter xml:id="language.operators" xmlns="http://docbook.org/ns/docbook" annotations="interactive">
  <title>Operatory</title>
@@ -42,6 +42,7 @@
  &language.operators.string;
  &language.operators.array;
  &language.operators.type;
+ &language.operators.functional;
 
 </chapter>
 <!-- Keep this comment at the end of the file