diff --git a/examples/test-embed.scm b/examples/test-embed.scm
new file mode 100644
index 0000000..4dd81d1
--- /dev/null
+++ b/examples/test-embed.scm
@@ -0,0 +1,86 @@
+(define at-uni? #t)
+(define pred string=?)
+
+(define obj-rules
+  (list 
+   (file-rx (rx (: (submatch "") (submatch (+ any)) (submatch ".o")))
+	    (list "%.c" "%.h")
+	    (lambda () (run (gcc -fPIC -c ,(string-append ($*) ".c")))))))
+
+(define lib-rules
+  (list 
+   (md5-% "lib%.so.1.0"
+	 (list "%.o")
+	 (lambda () (run (gcc -shared 
+			      ,(string-append "-Wl,-soname," ($=*) ".so.1") 
+			      -o ,($@) ,($<)))))
+
+   (file-% "lib%.so.1" 
+	 (list "lib%.so.1.0") 
+	 (lambda () (create-symlink ($<) ($@))))
+
+   (file-% "lib%.so" 
+	 (list "lib%.so.1") 
+	 (lambda () (create-symlink ($<) ($@))))))
+
+(define tex-rules 
+  (list 
+   (file-% "%.dvi"
+	   (list "%.tex")
+	   (lambda () (run (latex ,($<)))))
+   (file-% "%.pdf"
+	   (list "%.dvi")
+	   (lambda () (run (dvipdfm -o ,($@) ,($<)))))
+   (file-% "%.ps"
+	   (list "%.dvi")
+	   (lambda () (run (dvips -o ,($@) ,($<)))))))
+
+(define proggy
+  (if at-uni?
+      (file->rc "show-sqrt" 
+		(list "main.c" "libmymath.so.1" 
+		      "libwildio.so.1" "wildio.h" "mymath.h")
+		(lambda () (run (gcc -L ,(cwd) ,(ldflags) -rdynamic 
+				     -o ,($@) ,($<) 
+				     ,"libwildio.so.1" ,"libmymath.so.1" -lc))))
+      (file->rc "show-sqrt" 
+		(list "main.c" "libmymath.so.1" 
+		      "libwildio.so.1" "wildio.h" "mymath.h")
+		(lambda () (run (gcc -L ,(cwd) -rdynamic -o ,($@) ,($<) 
+				     ,"libwildio.so.1" ,"libmymath.so.1" -ldl))))))
+
+(define manuals
+  (let* ((prefixes (list "a" "b" "c" "d")))
+    (append 
+     (map (lambda (pre)
+	    (string-append pre "-manual.dvi"))
+	  prefixes)
+     (map (lambda (pre)
+	    (string-append pre "-manual.ps"))
+	  prefixes)
+     (map (lambda (pre)
+	    (string-append pre "-manual.pdf"))
+	  prefixes))))
+
+(define install
+  (always->rc "install"
+	      (append (list "show-sqrt") manuals)
+	      (lambda ()
+		(for-each (lambda (f) (display ">>> ") (display f) (newline)) ($+))
+		(display "install done.\n"))))
+
+(define clean 
+  (always->rc "clean"
+	      (list)
+	      (lambda ()
+		(for-each (lambda (f) 
+			    (delete-filesys-object (expand-file-name f (cwd))))
+			  (append manuals (list "show-sqrt"))))))
+
+(define rcs (list proggy install clean))
+(define commons (append obj-rules lib-rules tex-rules))
+
+(define rules (rcs+commons->rules pred rcs commons))
+;; (define rule-set (rules->rule-set rules))
+
+(define done (make rules (list "clean" "install")))
diff --git a/to-rule-set.scm b/to-rule-set.scm
index 7f3c3c9..7112cce 100644
--- a/to-rule-set.scm
+++ b/to-rule-set.scm
@@ -37,7 +37,7 @@
   (let ((maybe-fname (find (lambda (current)
 			     (pred fname (car current)))
 			   rcs)))
-    (if maybe-fname maybe-fname (error "lookup-fname: fname not found."))))
+    (if maybe-fname maybe-fname #f)))
 
 (define (lookup-rule pred fname rules)
   (let ((maybe-rule (find (lambda (current)