diff --git a/lib/scheme/cxr.scm b/lib/scheme/cxr.scm
new file mode 100644
index 00000000..df62b1dd
--- /dev/null
+++ b/lib/scheme/cxr.scm
@@ -0,0 +1,27 @@
+
+;; provide c[ad]{3,4}r
+
+(define (caaar x) (car (car (car x))))
+(define (caadr x) (car (car (cdr x))))
+(define (cadar x) (car (cdr (car x))))
+(define (caddr x) (car (cdr (cdr x))))
+(define (cdaar x) (cdr (car (car x))))
+(define (cdadr x) (cdr (car (cdr x))))
+(define (cddar x) (cdr (cdr (car x))))
+(define (cdddr x) (cdr (cdr (cdr x))))
+(define (caaaar x) (car (car (car (car x)))))
+(define (caaadr x) (car (car (car (cdr x)))))
+(define (caadar x) (car (car (cdr (car x)))))
+(define (caaddr x) (car (car (cdr (cdr x)))))
+(define (cadaar x) (car (cdr (car (car x)))))
+(define (cadadr x) (car (cdr (car (cdr x)))))
+(define (caddar x) (car (cdr (cdr (car x)))))
+(define (cadddr x) (car (cdr (cdr (cdr x)))))
+(define (cdaaar x) (cdr (car (car (car x)))))
+(define (cdaadr x) (cdr (car (car (cdr x)))))
+(define (cdadar x) (cdr (car (cdr (car x)))))
+(define (cdaddr x) (cdr (car (cdr (cdr x)))))
+(define (cddaar x) (cdr (cdr (car (car x)))))
+(define (cddadr x) (cdr (cdr (car (cdr x)))))
+(define (cdddar x) (cdr (cdr (cdr (car x)))))
+(define (cddddr x) (cdr (cdr (cdr (cdr x)))))
diff --git a/lib/scheme/cxr.sld b/lib/scheme/cxr.sld
new file mode 100644
index 00000000..3d65bf32
--- /dev/null
+++ b/lib/scheme/cxr.sld
@@ -0,0 +1,8 @@
+
+(define-library (scheme cxr)
+  (import (scheme))
+  (export
+   caaar caadr cadar caddr cdaar cdadr cddar cdddr
+   caaaar caaadr caadar caaddr cadaar cadadr caddar cadddr
+   cdaaar cdaadr cdadar cdaddr cddaar cddadr cdddar cddddr)
+  (include "cxr.scm"))