commit 808987c2639d2b43f18878832eef48a2775a83b7
Author:     Aaron Brooks <aaron@brooks1.net>
AuthorDate: Sat Sep 1 20:52:36 2012 -0400
Commit:     Aaron Brooks <aaron@brooks1.net>
CommitDate: Sat Sep 1 21:01:05 2012 -0400

    retractions: Fix bug converting 'set from PersistentHashSet to LazySeq.
    
    This issue does not affect external correctness but will adversely
    affect performance in the presence of duplicated facts.

diff --git a/src/main/clojure/clojure/core/logic.clj b/src/main/clojure/clojure/core/logic.clj
index a0ec68f..8eadf0e 100644
--- a/src/main/clojure/clojure/core/logic.clj
+++ b/src/main/clojure/clojure/core/logic.clj
@@ -2769,7 +2769,7 @@
      (let [rel-ns (:ns (meta rel))
            rel-set (var-get (ns-resolve rel-ns (set-sym (.name rel) arity)))
            tuples (map vec tuples)]
-       (swap! rel-set (fn [s] (remove #(some #{%} tuples) s)))
+       (swap! rel-set (fn [s] (reduce disj s tuples)))
        (let [indexes (indexes-for rel arity)]
          (doseq [[o i] indexes]
            (let [index (var-get (ns-resolve rel-ns (index-sym (.name rel) arity o)))]