Changeset 2792

Timestamp:

2015-06-20T21:21:46-07:00 (9 years ago)

Author:

Marek Rychlik

Message:

* empty log message *

File:

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

branches/f4grobner/polynomial.lisp

@@ -192 +192 @@
 
 
-(defun multiply-term-by-termlist (term termlist)
-  (mapcan #'(lambda (term-termlist) (term-mul-lst term term-termlist)) termlist))
-
-(defun multiply-termlist-by-term (termlist term)
-  (mapcan #'(lambda (term-termlist) (term-mul-lst term-termlist term)) termlist))
+(defun multiply-term-by-termlist-dropping-zeros (term termlist)
+  "A product of a term TERM by a list of term, TERMLIST.
+Takes into accound divisors of zero in the ring, by
+deleting zero terms."
+  (mapcan #'(lambda (other-term) 
+              (let ((prod (term-multiply term other-term)))
+                (cond 
+                  ((r-zerop prod) nil)
+                  (t (list prod)))))
+          termlist))
+
+(defun multiply-termlist-by-term-dropping-zeros (termlist term)
+  "A product of a termlist TERMLIST by a term TERM>
+Takes into accound divisors of zero in the ring, by
+deleting zero terms."
+  (mapcan #'(lambda (other-term) 
+              (let ((prod (term-multiply other-term term)))
+                (cond 
+                  ((r-zerop prod) nil)
+                  (t (list prod)))))
+          termlist))