bn: Introduce the section on interaction graphs.

bn.rkt

@@ -96,3 +96,22 @@
 
 ;;; A shortcut for make-bn-forms.
 (define-syntax-rule (bn forms) (make-bn-forms forms))
+
+
+;;; ============================
+;;; Inferring interaction graphs
+;;; ============================
+
+;;; I allow any syntactic forms in definitions of Boolean functions.
+;;; I can still find out which Boolean variables appear in those
+;;; syntactic form, but I have no reliable syntactic means of finding
+;;; out what kind of action do they have (inhibition or activation)
+;;; since I cannot do Boolean minimisation (e.g., I cannot rely on not
+;;; appearing before a variable, since (not (not a)) is equivalent
+;;; to a).  On the other hand, going through all Boolean states is
+;;; quite resource-consuming and thus not always useful.
+;;;
+;;; In this section I provide inference of both unsigned and signed
+;;; interaction graphs, but since the inference of signed interaction
+;;; graphs is based on analysing the dynamics of the networks, it may
+;;; be quite resource-consuming.