Changeset 4463 for branches/f4grobner/buchberger.lisp

Timestamp:

2016-06-14T19:35:34-07:00 (8 years ago)

Author:

Marek Rychlik

Message:

 

File:

• branches/f4grobner/buchberger.lisp (modified) (3 diffs)

branches/f4grobner/buchberger.lisp

@@ -26 +26 @@
         :ring
         )
-  (:export "BUCHBERGER" "PARALLEL-BUCHBERGER")
+  (:export "BUCHBERGER" "PARALLEL-BUCHBERGER" "GROBNER-MEMBER" "GROBNER-SUBSETP" "GROBNER-EQUAL")
   (:documentation "Buchberger Algorithm Implementation."))
 
@@ -49 +49 @@
                     (grobner-test (subseq f 0 start) (subseq f 0 start)))
   ;;Initialize critical pairs
-  (let ((b (make-critical-pair-queue *normal-strategy* f start))
+  (let ((b (make-critical-pair-queue *min-total-degree-strategy* f start))
         (b-done (make-hash-table :test #'equal)))
     (declare (type critical-pair-queue b) (type hash-table b-done))
@@ -85 +85 @@
         (setf (gethash (list (critical-pair-first pair) (critical-pair-second pair)) b-done)
               t)))))
+
+
+(defun grobner-member (p g)
+  "Returns T if a polynomial P belongs to the ideal generated by the
+polynomial list G, which is assumed to be a Grobner basis. Returns NIL otherwise."
+  (universal-zerop (normal-form p g nil)))
+
+
+(defun grobner-subsetp (g1 g2)
+  "Returns T if a list of polynomials G1 generates
+an ideal contained in the ideal generated by a polynomial list G2,
+both G1 and G2 assumed to be Grobner bases. Returns NIL otherwise."
+  (every #'(lambda (p) (grobner-member p g2)) g1))
+
+
+(defun grobner-equal (g1 g2)
+  "Returns T if two lists of polynomials G1 and G2, assumed to be Grobner bases,
+generate  the same ideal, and NIL otherwise."
+  (and (grobner-subsetp g1 g2) (grobner-subsetp g2 g1)))