example: Mention dds/functions.

example/example.org

@@ -1,6 +1,6 @@
 #+TITLE: Examples of usage of =dds=
 
-#+PROPERTY: header-args:racket :prologue "#lang racket\n(require graph dds/networks dds/utils)"
+#+PROPERTY: header-args:racket :prologue "#lang racket\n(require graph dds/networks dds/utils dds/functions)"
 
 * Introduction
   This document shows some examples of usage of the modules in =dds=
@@ -327,13 +327,18 @@ tab
    It also draws double-sided edges as undirected edges (e.g., in the
    preceding graph, b depends on c and c depends on b).
 
-* =dds/networks=
+* =dds/networks= and =dds/functions=
   The [[../networks.rkt][=dds/networks=]] is a module for working with different network
   models.  A network is a set of variables which are updated according
   to their corresponding update functions.  The variables to be
   updated at each step are given by the mode.  This model can
   generalise Boolean networks, TBANs, multivalued networks, etc.
 
+  [[file:../functions.rkt][=dds/functions=]] is a module for working with the functions
+  underlying the network models.  Similarly to =dds/networks=, it
+  provides primitives for tabulating functions, reconstructing
+  functions from tables, generating random functions, etc.
+
 ** Boolean networks
    Consider the following Boolean network:
    #+NAME: simple-bn