ApCoCoA-1:NCo.BLW

This article is about a function from ApCoCoA-1.

NCo.BLW

The leading word (or term) of a non-zero polynomial in a free monoid ring over the binary field F_{2}={0,1}.

Syntax

NCo.BLW(F:LIST):STRING
NCo.BLT(F:LIST):STRING

Description

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.

Please set ring environment alphabet (or set of indeterminates) X and word ordering via the functions NCo.SetX and NCo.SetOrdering, respectively, before calling this function. The default ordering is the length-lexicographic ordering ("LLEX"). For more information, please check the relevant functions.

• @param F: a non-zero polynomial in the free monoid ring F_{2}<X>. Each polynomial is represented as a LIST of words (or terms) in <X>. Each word is represented as a STRING. For example, xy^2x is represented as "xyyx", and the identity is represented as the empty string "". Thus, the polynomial f=xy-y+1 is represented as F:=["xy", "y", ""]. The zero polynomial 0 is represented as the empty LIST [].

• @return: a STRING which represents the leading word of F with respect to the current word ordering. If F=0, the function returns nothing.

Example

NCo.SetX(<quotes>xX</quotes>);
NCo.SetOrdering(<quotes>LLEX</quotes>);
F1:=[<quotes>xX</quotes>,<quotes>Xx</quotes>];
NCo.BLW(F1);
xX
-------------------------------
NCo.BLW([]);
-------------------------------

See also

NCo.SetOrdering

NCo.SetX

Introduction to CoCoAServer