Changeset 4035

Timestamp:

2016-05-31T15:59:20-07:00 (9 years ago)

Author:

Marek Rychlik

Message:

* empty log message *

File:

• branches/f4grobner/polynomial.lisp (modified) (1 diff)

branches/f4grobner/polynomial.lisp

@@ -204 +204 @@
 
 (defmethod unary-inverse :before ((self poly))
-  (with-slots (termlist)
-      (assert (and (= (length termlist) 1) (zerop (total-degree (car termlist)) 0))
-              nil
-              "To be invertible, the polynomial must have 1 term of total degree 0.")))
-
-(defmethod unary-inverse ((self poly))
+  "Checks invertibility of a polynomial SELF. To be invertable, the
+polynomial must be an invertible, constant polynomial."
   (with-slots (termlist)
       self
-    (setf (car termlist) (unary-inverse (car termlist)))))
+    (assert (and (= (length termlist) 1) (zerop (total-degree (car termlist))))
+            nil
+            "To be invertible, the polynomial must have 1 term of total degree 0.")))
+
+(defmethod unary-inverse ((self poly))
+  "Returns the unary inverse of a polynomial SELF."
+  (with-slots (termlist)
+      self
+    (setf (car termlist) (unary-inverse (car termlist)))
+    self))
 
 (defmethod multiply-by ((self poly) (other monom))