diff --git a/README.md b/README.md
index 0b6e4a7..ec9af86 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,4 @@
 # knapsack
-A solver for the knapsack problem in Prolog (Eclipse CSP)
+
+A solver for the knapsack problem in Eclipse CSP-flavoured Prolog.
+Nothing too fancy. Have fun!
diff --git a/knapsack.ecl b/knapsack.ecl
new file mode 100644
index 0000000..e4a3725
--- /dev/null
+++ b/knapsack.ecl
@@ -0,0 +1,20 @@
+:-lib(fd).
+:-lib(fd_global).
+:-lib(branch_and_bound).
+
+knapsack(P, W, C, T, V) :-
+  length(P, N),
+  length(V, N),
+  minlist(W, Min),
+  D is C // Min,
+  V::0..D,
+  C #>= W*V,
+  T #= P*V,
+  sumlist(V, S),
+  O #= (-1)*T,
+  Negs #= (-1)*T,
+  bb_min(labeling(V), O, V, _, _, _),
+  bb_min(labeling(V), Negs, _).
+
+test(P, V):-
+  knapsack([60, 100, 120], [15, 20, 30], 325, P, V).