1 files changed, 6 insertions, 6 deletions
diff --git a/Makefile b/Makefile
index f86226c..c30f9d8 100644
--- a/Makefile
+++ b/Makefile
@@ -1,16 +1,16 @@
-.PHONY: clean all
+subdirs := lists
 
-all: huffman-encode.cert perm.cert
+.PHONY: clean all $(subdirs)
+
+all: huffman-encode.cert $(subdirs)
 
 huffman-encode.cert: huffman-encode.lisp
 	-rm -f $@
 	acl2 <<< '(CERTIFY-BOOK "$(basename $@)")'
 	test -f $@
 
-perm.cert: perm.lisp
-	-rm -f $@
-	acl2 <<< '(CERTIFY-BOOK "$(basename $@)")'
-	test -f $@
+$(subdirs):
+	$(MAKE) -C $@
 
 clean:
 	rm -f *.{cert,fasl,port,lx64fsl}