rs: Start.

rs-tests.rkt

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+#lang typed/racket
+
+;;; Tests for dds/rs.
+
+(require typed/rackunit "rs.rkt")
+
+(test-case "Basic definitions"
+  (let ([r (reaction (set 'a) (set 'b) (set 'c))]
+        [s1 (set 'a 'c)]
+        [s2 (set 'a 'b)])
+    (check-true (enabled? r s1))
+    (check-false (enabled? r s2))))

rs.rkt

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+#lang typed/racket
+
+;;; dds/rs
+
+;;; Definitions for working with reaction systems.
+
+(provide
+ ;; Structures
+ reaction
+ ;; Functions
+ enabled?)
+
+;;; =================
+;;; Basic definitions
+;;; =================
+
+;;; A species is a symbol.
+(define-type Species Symbol)
+
+;;; A reaction is a triple of sets, giving the reactants, the
+;;; inhibitors, and the products, respectively.
+(struct reaction ([reactants : (Setof Symbol)]
+                  [inhibitors : (Setof Symbol)]
+                  [products : (Setof Symbol)]))
+
+;;; A reaction is enabled on a set if all of its reactants are in the
+;;; set and none of its inhibitors are.
+(: enabled? (-> reaction (Setof Symbol) Boolean))
+(define/match (enabled? r s)
+  [((reaction r i p) s)
+   (and (subset? r s) (set-empty? (set-intersect i s)))])