Changeset 2790

Timestamp:

2015-06-20T21:12:20-07:00 (9 years ago)

Author:

Marek Rychlik

Message:

* empty log message *

File:

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

branches/f4grobner/polynomial.lisp

@@ -190 +190 @@
   (mapc #'unary-minus (poly-termlist self))
   self)
+
+
+(defun term-mul-lst (ring term1 term2)
+  "A special version of term multiplication. Returns (LIST TERM) where
+TERM is the product of the terms TERM1 TERM2, or NIL when the product
+is 0. This definition takes care of divisors of 0 in the coefficient
+ring."
+  (let ((c (r* (term-coeff term1) (term-coeff term2))))
+    (unless (r-zerop c)
+      (list (make-instance 'term 
+                           :monom (r* (term-monom term1) (term-monom term2)) 
+                           :coeff c)))))
+
+(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))