ApCoCoA-1:NCo.LW
| This article is about a function from ApCoCoA-1. |
NCo.LW
The leading word (or term) of a non-zero polynomial in a free monoid ring.
Syntax
NCo.LW(F:LIST):STRING NCo.LT(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 coefficient field K, alphabet (or set of indeterminates) X and ordering via the functions NCo.SetFp, NCo.SetX and NCo.SetOrdering, respectively, before using this function. The default coefficient field is Q, and the default ordering is the length-lexicographic ordering ("LLEX"). For more information, please check the relevant functions.
@param F: a non-zero polynomial in K<X>. Each polynomial is represented as a LIST of LISTs, which are pairs of form [C, W] where C is a coefficient and W is a word (or term). Each polynomial is represented as a LIST of monomials, which are LISTs of the form [C, W] where W is a word in <X> and C is the coefficient of W. For example, the polynomial f=xy-y+1 is represented as F:=[[1,"xy"], [-1, "y"], [1,""]]. The zero polynomial 0 is represented as the empty LIST [].
@return: a STRING which represents the leading term of F with respect to the current word ordering. If F=0, the function returns nothing.
Example
NCo.SetX("abc");
F:=[[1,"ab"],[1,"aa"],[1,"bb"],[1,"bab"]];
NCo.LW(F); -- LLEX ordering (default ordering)
bab
-------------------------------
NCo.SetOrdering("ELIM");
NCo.LW(F);
aa
-------------------------------
NCo.LW([]);
See also
