diff --git a/networks.rkt b/networks.rkt
index 217c110..860ff86 100644
--- a/networks.rkt
+++ b/networks.rkt
@@ -4,16 +4,24 @@
   (require "utils.rkt" "functions.rkt"
            typed/graph racket/random)
 
+  (module+ test
+    (require typed/rackunit))
+
   (provide
-   State UpdateFunction DomainMapping)
+   State UpdateFunction DomainMapping
+   (struct-out network) Network)
 
   (define-type (State a) (VariableMapping a))
   (define-type (UpdateFunction a) (-> (State a) a))
   (define-type (DomainMapping a) (VariableMapping (Listof a)))
+
+  (struct (a) network ([functions : (VariableMapping (UpdateFunction a))]
+                       [domains : (DomainMapping a)])
+    #:transparent
+    #:type-name Network)
   )
 
 (require 'typed)
-(provide)
 
 
 (require (except-in "utils.rkt" lists-transpose) (submod "utils.rkt" untyped)
@@ -183,15 +191,6 @@
 ;;; values in their domains.
 (define domain-mapping/c (hash/c variable? list?))
 
-;;; A network consists of a mapping from its variables to its update
-;;; variables, as a well as of a mapping from its variables to
-;;; their domains.
-;;;
-;;; The domain mapping does not have to assign domains to all
-;;; variables (e.g., it may be empty), but in this case the functions
-;;; which need to know the domains will not work.
-(struct network (functions domains) #:transparent)
-
 ;;; Builds a network from a given hash table assigning functions to
 ;;; variables by attributing Boolean domains to every variable.
 (define (make-boolean-network funcs)
diff --git a/scribblings/networks.scrbl b/scribblings/networks.scrbl
index fb61c1f..77aefb6 100644
--- a/scribblings/networks.scrbl
+++ b/scribblings/networks.scrbl
@@ -11,7 +11,7 @@
   (parameterize ([sandbox-output 'string]
   		 [sandbox-error-output 'string]
 		 [sandbox-memory-limit 50])
-   (make-evaluator 'typed/racket #:requires '("networks.rkt"))))
+   (make-evaluator 'typed/racket #:requires '((submod "networks.rkt" typed)))))
 
 @(define-syntax-rule (ex . args)
   (examples #:eval networks-evaluator . args))
@@ -48,6 +48,35 @@ their domains.
 
 }
 
+@defstruct*[network ([functions (VariableMapping (UpdateFunction a))]
+		     [domains (DomainMapping a)])]{
+
+A network consists of a mapping from its variables to its update variables, as
+a well as of a mapping from its variables to their domains.
+
+Instances of @racket[network] have the type @racket[Network].
+
+}
+
+@defidform[#:kind "type" Network]{
+
+The type of the instances of @racket[Network].
+
+@ex[
+(: or-func (UpdateFunction Boolean))
+(define (or-func s)
+  (or (hash-ref s 'a) (hash-ref s 'b)))
+
+(: and-func (UpdateFunction Boolean))
+(define (and-func s)
+  (and (hash-ref s 'a) (hash-ref s 'b)))
+
+(network (hash 'a or-func
+               'b and-func)
+         (hash 'a '(#f #t)
+               'b '(#f #t)))
+]}
+
 @section{Syntactic description of networks}
 
 @section{Inferring interaction graphs}