diff --git a/modules/radix/combinators.scm b/modules/radix/combinators.scm
index 4332d17..b110866 100644
--- a/modules/radix/combinators.scm
+++ b/modules/radix/combinators.scm
@@ -6,7 +6,9 @@
             any-of
             conjoin
             disjoin
-            inclusive-disjoin))
+            inclusive-disjoin
+            flip
+            swap))
 
 (define ((all-of pred) lst)
   (null? (filter (negate pred) lst)))
@@ -37,3 +39,8 @@
             ((not (apply head-pred args)) (loop tail-preds))
             (else #f)))))
 
+(define ((flip proc) . args)
+  (apply proc (reverse args)))
+
+(define ((swap proc) arg1 arg2 . args)
+  (apply proc arg2 arg1 args))