diff --git a/collects/mrflow/assoc-set-hash.ss b/collects/mrflow/assoc-set-hash.ss
index fbafda956a..9e611d330c 100644
--- a/collects/mrflow/assoc-set-hash.ss
+++ b/collects/mrflow/assoc-set-hash.ss
@@ -46,6 +46,7 @@
    (assoc-set-union ((assoc-set? assoc-set? (any/c any/c . -> . any)) ((symbols 'new 'first 'second)) . opt-> . assoc-set?))
    (assoc-set-intersection ((assoc-set? assoc-set? (any/c any/c . -> . any)) ((symbols 'new 'first 'second)) . opt-> . assoc-set?))
    (assoc-set-difference ((assoc-set? assoc-set?) ((symbols 'new 'first 'second)) . opt-> . assoc-set?))
+   (assoc-set-subset? (assoc-set? assoc-set? . -> . boolean?))
    )
   
   ; (opt 'equal) -> assoc-set
@@ -260,4 +261,14 @@
             ;[else (argexn:raise-arg-mismatch-exn "assoc-set-difference" '(union new first second) which-set)]
             )))))
   
-  )
+  ; assoc-set assoc-set -> boolean
+  ; compares keys only
+  (define (assoc-set-subset? assoc-set1 assoc-set2)
+    (let/ec k
+      (hash-table-for-each (assoc-set-table assoc-set1)
+                           (lambda (key value)
+                             (unless (assoc-set-in? assoc-set2 key)
+                               (k #f))))
+      #t))
+  
+ )
diff --git a/collects/mrflow/assoc-set-list.ss b/collects/mrflow/assoc-set-list.ss
index 85c5bf162c..341fb624f2 100644
--- a/collects/mrflow/assoc-set-list.ss
+++ b/collects/mrflow/assoc-set-list.ss
@@ -48,6 +48,7 @@
    (assoc-set-union ((assoc-set? assoc-set? (any/c any/c . -> . any)) ((symbols 'new 'first 'second)) . opt-> . assoc-set?))
    (assoc-set-intersection ((assoc-set? assoc-set? (any/c any/c . -> . any)) ((symbols 'new 'first 'second)) . opt-> . assoc-set?))
    (assoc-set-difference ((assoc-set? assoc-set?) ((symbols 'new 'first 'second)) . opt-> . assoc-set?))
+   (assoc-set-subset? (assoc-set? assoc-set? . -> . boolean?))
    )
   
   ; (opt 'equal) -> assoc-set
@@ -357,4 +358,11 @@
            (set-assoc-set-table! assoc-set2 (assoc-set-table new-assoc-set))
            assoc-set2]))))
   
+  ; assoc-set assoc-set -> boolean
+  ; compares keys only
+  (define (assoc-set-subset? assoc-set1 assoc-set2)
+    (andmap (lambda (key value)
+              (assoc-set-in? assoc-set2 key))
+            (assoc-set-table assoc-set1)))
+  
   )
diff --git a/collects/mrflow/info.ss b/collects/mrflow/info.ss
deleted file mode 100644
index c8f768de66..0000000000
--- a/collects/mrflow/info.ss
+++ /dev/null
@@ -1,14 +0,0 @@
-
-(module info (lib "infotab.ss" "setup")
-        
-  ; for mzc
-  (define compile-omit-files '("test.ss" "tests.ss" "primitives.ss"))
-  
-  ; for DrScheme
-  (define name "MrFlow")
-  (define tools '(("gui.ss")))
-  (define tool-icons '(("mrflow.gif" "icons")))
-  ; this name shows up in the "About Drscheme" menu
-  (define tool-names '("MrFlow Static Debugger"))
-  (define tool-urls '("http://www.plt-scheme.org/software/mrflow/"))
-  )
diff --git a/collects/mrflow/set-hash.ss b/collects/mrflow/set-hash.ss
index 40cca6b57c..89ea1594f9 100644
--- a/collects/mrflow/set-hash.ss
+++ b/collects/mrflow/set-hash.ss
@@ -44,6 +44,7 @@
    (set-union ((set? set?) ((symbols 'new 'first 'second)) . opt-> . set?))
    (set-intersection ((set? set?) ((symbols 'new 'first 'second)) . opt-> . set?))
    (set-difference ((set? set?) ((symbols 'new 'first 'second)) . opt-> . set?))
+   (set-subset? (set? set? . -> . boolean?))
    )
   
   ; (opt 'equal) -> set
@@ -242,4 +243,13 @@
              (set-set-cardinality! set2 (set-cardinality new-set))
              set2])))))
   
+  ; set set -> boolean
+  (define (set-subset? set1 set2)
+    (let/ec k
+      (hash-table-for-each (set-table set1)
+                           (lambda (value dummy)
+                             (unless (set-in? set2 value)
+                               (k #f))))
+      #t))
+  
   )
diff --git a/collects/mrflow/set-list.ss b/collects/mrflow/set-list.ss
index fe010ba465..ed91259201 100644
--- a/collects/mrflow/set-list.ss
+++ b/collects/mrflow/set-list.ss
@@ -47,6 +47,7 @@
    (set-union ((set? set?) ((symbols 'new 'first 'second)) . opt-> . set?))
    (set-intersection ((set? set?) ((symbols 'new 'first 'second)) . opt-> . set?))
    (set-difference ((set? set?) ((symbols 'new 'first 'second)) . opt-> . set?))
+   (set-subset? (set? set? . -> . boolean?))
    )
   
   ; (opt 'equal) -> set
@@ -337,4 +338,10 @@
            (set-set-table! set2 (set-table new-set))
            set2]))))
   
+  ; set set -> boolean
+  (define (set-subset? set1 set2)
+    (andmap (lambda (value)
+              (set-in? set2 value))
+            (set-table set1)))
+  
   )