Category:ApCoCoA-1:Package gbmr: Difference between revisions

From ApCoCoAWiki
No edit summary
No edit summary
Line 1: Line 1:
Package gbmr is designed to compute Groebner bases in monoid rings.
Package gbmr is designed to provide basic operations over monoid rings and compute Groebner bases of finite generated ideals.


For the field of rationals Q and a monoid M presented by a string rewriting system, let Q[M] denote the ring of all finite formal sums (called polynomials) a_{1}*w_{1}+ a_{2}*w_{2} +...+a_{n}*w_{n} with coefficients a_{i} in Q\{0} and terms w_{i} in M. This ring is called the <em>monoid ring</em> of M over Q.
For the field of rationals <em>Q</em> and a monoid <em>M</em> presented by a string rewriting system (<em>Alphabet</em>, <em>Rs</em>), where <em>Alphabet</em> is finite alphabet and <em>Rs</em> is set of relations, let Q[M] denote the ring of all finite formal sums (called polynomials) a_{1}*w_{1}+ a_{2}*w_{2} +...+a_{n}*w_{n} with coefficients a_{i} in Q\{0} and terms w_{i} in M. This ring is called the <em>monoid ring</em> of M over Q.


Let p, f be two non-zero polynomials in Q[M]. We say f prefix reduces p to q at a monomial a*t of p in one step, denoted by p-->_{f}q if
Let p, f be two non-zero polynomials in Q[M]. We say f prefix reduces p to q at a monomial a*t of p in one step, denoted by p-->_{f}q if

Revision as of 11:22, 22 October 2009

Package gbmr is designed to provide basic operations over monoid rings and compute Groebner bases of finite generated ideals.

For the field of rationals Q and a monoid M presented by a string rewriting system (Alphabet, Rs), where Alphabet is finite alphabet and Rs is set of relations, let Q[M] denote the ring of all finite formal sums (called polynomials) a_{1}*w_{1}+ a_{2}*w_{2} +...+a_{n}*w_{n} with coefficients a_{i} in Q\{0} and terms w_{i} in M. This ring is called the monoid ring of M over Q.

Let p, f be two non-zero polynomials in Q[M]. We say f prefix reduces p to q at a monomial a*t of p in one step, denoted by p-->_{f}q if

 (1) LT(f)w = t for some w in M, i.e., LT(f) is a prefix of t, and
 (2) q = p-a*LT(f)^{-1}*f*w.

A set G is said to be a Groebner basis with respect to the reduction -->, if <-->_{G} = Equiv_{Ideal(G)} and -->_{G} is confluent.


Please note: The function(s) explained on this page is/are using the ApCoCoAServer. You will have to start the ApCoCoAServer in order to use it/them.