diff --git a/collects/mzlib/functior.ss b/collects/mzlib/functior.ss
index 512e463..06dc72d 100644
--- a/collects/mzlib/functior.ss
+++ b/collects/mzlib/functior.ss
@@ -197,22 +197,29 @@
 	 [(f init l) (fold-one f init l)]
 	 [(f init l . ls) (fold-n f init (cons l ls))]))))
 
+   (define make-find
+     (lambda (name whole-list?)
+       (polymorphic
+	(lambda (f list)
+	  (unless (and (procedure? f)
+		       (procedure-arity-includes? f 1))
+		  (raise-type-error name "procedure (arity 1)" f))
+	  (let loop ([l list])
+	    (cond
+	     [(null? l) #f]
+	     [(not (pair? l)) 
+	      (raise (make-exn:application:list
+		      (format "~a: second argument must be a (proper) list; given ~e" name list)
+		      ((debug-info-handler))
+		      list))]
+	     [(f (car l)) (if whole-list? l (car l))]
+	     [else (loop (cdr l))]))))))
+
    (define assf
-     (polymorphic
-      (lambda (f list)
-	(unless (and (procedure? f)
-		     (procedure-arity-includes? f 1))
-		(raise-type-error 'assf "procedure (arity 1)" f))
-	(let loop ([l list])
-	  (cond
-	   [(null? l) #f]
-	   [(not (pair? l)) 
-	    (raise (make-exn:application:list
-		    (format "assf: second argument must be a (proper) list; given ~e" list)
-		    ((debug-info-handler))
-		    list))]
-	   [(f (car l)) (car l)]
-	   [else (loop (cdr l))])))))
+     (make-find 'assf #f))
+
+   (define memf
+     (make-find 'memf #t))
 
    (define filter
      (polymorphic
diff --git a/collects/mzlib/traceld.ss b/collects/mzlib/traceld.ss
index b627ee7..34cd44a 100644
--- a/collects/mzlib/traceld.ss
+++ b/collects/mzlib/traceld.ss
@@ -1,43 +1,2 @@
 
-(let ([load (current-load)]
-      [load-extension (current-load-extension)]
-      [tab ""])
-  (let ([mk-chain
-	 (lambda (load)
-	   (lambda (filename)
-	     (fprintf (current-error-port)
-		      "~aloading ~a at ~a~n" 
-		      tab filename (current-process-milliseconds))
-	     (begin0
-	      (let ([s tab])
-		(dynamic-wind
-		 (lambda () (set! tab (string-append " " tab)))
-		 (lambda () 
-		   (if (regexp-match "_loader" filename)
-		       (let ([f (load filename)])
-			 (lambda (sym)
-			   (fprintf (current-error-port)
-				    "~atrying ~a~n" tab sym)
-			   (let ([loader (f sym)])
-			     (and loader
-				  (lambda ()
-				    (fprintf (current-error-port)
-					     "~astarting ~a at ~a~n" tab sym
-					     (current-process-milliseconds))
-				    (let ([s tab])
-				      (begin0
-				       (dynamic-wind
-					(lambda () (set! tab (string-append " " tab)))
-					(lambda () (loader))
-					(lambda () (set! tab s)))
-				       (fprintf (current-error-port)
-						"~adone ~a at ~a~n"
-						tab sym
-						(current-process-milliseconds)))))))))
-		       (load filename)))
-		 (lambda () (set! tab s))))
-	      (fprintf (current-error-port)
-		       "~adone ~a at ~a~n"
-		       tab filename (current-process-milliseconds)))))])
-    (current-load (mk-chain load))
-    (current-load-extension (mk-chain load-extension))))
+(invoke-unit/sig (require-relative-library "traceldr.ss"))