Changeset b6c31c in git for Singular/LIB/ncfactor.lib

Timestamp:

Feb 1, 2019, 1:55:23 AM (5 years ago)

Author:

Viktor Levandovskyy <levandov@…>

Branches:

(u'spielwiese', '8e0ad00ce244dfd0756200662572aef8402f13d5')

Children:

ad62229092fc8ebe6427ffe920f831abe60d4619

Parents:

c309bd9ad3a2f9f7486a6f07d6981cb894b5aae2

Message:

doc and example added

File:

• Singular/LIB/ncfactor.lib (modified) (5 diffs)

Singular/LIB/ncfactor.lib

@@ -1 +1 @@
 ///////////////////////////////////////////////////////////
-version = "$Id$";
+version="version ncfactor.lib 4.0.0.0 _2017 "; //$Id$
 category="Noncommutative";
 info="
@@ -10 +10 @@
 @* are implemented for several types of algebras, namely
 @* - finitely presented (and also free) associative algebras (Letterplace subsystem)
-@* - G-algebras, including (q)-Weyl and (q)-shift algebras in 2n variables
+@* - G-algebras (Plural subsystem), including (q)-Weyl and (q)-shift algebras in 2n variables
 @* The determination of the best algorithm available for users input is done
 @* automatically in the procedure ncfactor().
@@ -18 +18 @@
 
 PROCEDURES:
-  ncfactor(h);               Factorization in any finitely presented algebra (incl. G-algebras)
+  ncfactor(h);               Factorization in any finitely presented algebra (incl. G-algebra)
   facWeyl(h);                Factorization in the n'th Weyl algebra
   facFirstWeyl(h);           Factorization in the first Weyl algebra
@@ -11066 +11066 @@
 - There exists at least one variable in the ring.
 NOTE:
+- works for both PLURAL and LETTERPLACE subsystems
 - Every entry of the output list is a list with factors for one possible factorization.
   The first factor is always a constant (1, if no nontrivial constant
@@ -11149 +11150 @@
 {
   "EXAMPLE:";echo=2;
+  // first, an example with PLURAL 
   def R = makeUsl2();
   setring(R);
   poly p = e^3*f+e^2*f^2-e^3+e^2*f+2*e*f^2-3*e^2*h-2*e*f*h-8*e^2
            +e*f+f^2-4*e*h-2*f*h-7*e+f-h;
+  ncfactor(p);
+  kill R;
+  // an example with LETTERPLACE
+  LIB "freegb.lib";
+  ring r = 0,(x,y),Dp;
+  def R = freeAlgebra(r,5); setring(R);
+  poly p = x*y*x - x;
   ncfactor(p);
 }