diff --git a/src/anromero/homotopy.lisp b/src/anromero/homotopy.lisp
index 91689a3..8fcd8d5 100644
--- a/src/anromero/homotopy.lisp
+++ b/src/anromero/homotopy.lisp
@@ -57,7 +57,7 @@
          (result (homology-format  (eval ft) (1+ indx))))
     (if (= (1+ indx) n-hom)
         (homology-format (eval ft) n-hom)
-      (if (string= "NIL" result) result
+      (if (string= "NIL" result) nil
           (if (string= "Z " result)
               (compute-homotopy-z-xslt n-hom ft (1+ indx))
             (if (string= "Z/2Z " result)
@@ -74,7 +74,7 @@
          (result (homology-format (eval ft) (1+ indx))))
     (if (= (1+ indx) n-hom)
         (homology-format (eval ft) n-hom)
-      (if (string= "NIL" result) result
+      (if (string= "NIL" result) nil
           (if (string= "Z " result)
               (compute-homotopy-z-xslt n-hom ft (1+ indx))
             (if (string= "Z/2Z " result)
@@ -91,7 +91,7 @@
          (result (homology-format  (eval ft) (1+ indx))))
     (if (= (1+ indx) n-hom)
         (homology-format (eval ft) n-hom)
-      (if (string= "NIL" result) result
+      (if (string= "NIL" result) nil
           (if (string= "Z " result)
               (compute-homotopy-z-xslt n-hom ft (1+ indx))
             (if (string= "Z/2Z " result)
@@ -103,7 +103,7 @@
 
 (DEFUN SPLIT-COMPONENTS (string)
   (let ((term (if (string= string "") "" 
-                (if (string= string "NIL") NIL
+                (if (string= string "NIL") nil
                 (subseq string 0 2)))))
     (if (string= term "Z ")
         (cons 1 (split-components (subseq string 2)))
@@ -136,7 +136,7 @@
          (result (homology-format ft (1+ indx))))
     (if (= (1+ indx) n-hom)
         (homology-format (eval ft) n-hom)
-      (if (string= "NIL" result) result
+      (if (string= "NIL" result) nil
           (if (string= "Z " result)
               (compute-homotopy-z-xslt n-hom ft (1+ indx))
             (if (string= "Z/2Z " result)
diff --git a/src/anromero/resolutions.lisp b/src/anromero/resolutions.lisp
index 1eda64b..0841a50 100644
--- a/src/anromero/resolutions.lisp
+++ b/src/anromero/resolutions.lisp
@@ -426,7 +426,8 @@
    (type cmprf grcmpr zgcmpr)
    (type function grmult)
    (type intr-zgmrph intr)
-   (type zgcmbn zgcmbn))
+   ;;(type zgcmbn zgcmbn)
+)
   (the cmbn
     (with-cmbn (degr list) zgcmbn
       (if list
@@ -456,7 +457,8 @@
   (declare
    (type intr-zgmrph intr)
    (type cmprf grcmpr zgcmpr)
-   (type zgcmbn zgcmbn))
+   ;;(type zgcmbn zgcmbn)
+)
 
   (the cmbn
     (with-cmbn (degr list) zgcmbn
@@ -533,7 +535,8 @@
 (DEFUN ZGMRPH-ZGCMBN-? (ZGmrph zgcmbn)
   (declare
    (type zg-morphism zgmrph)
-   (type zgcmbn zgcmbn))
+   ;;(type zgcmbn zgcmbn)
+)
   (the cmbn
     (with-slots (trgt zgintr zgstrt ) zgmrph
       (declare
@@ -648,7 +651,7 @@
 
 
 (DEFUN ZGCMBN-TWI (zgcmpr zgcmbn)
-  (declare (type zgcmbn zgcmbn))
+  ;;(declare (type zgcmbn zgcmbn))
   (with-cmbn (degr list) zgcmbn
     (if list
         (let* ((cmbn-list +empty-list+))