ApCoCoA-1:NC.Mul

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NC.Mul

Multiplication of two polynomials in a non-commutative polynomial ring.

Syntax

NC.Mul(F1:LIST, F2:LIST):LIST

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 non-commutative polynomial ring (via the command Use) and word ordering (via the function NC.SetOrdering) before calling this function. The default word ordering is the length-lexicographic ordering ("LLEX"). For more information, please check the relevant commands and functions.

  • @param F1, F2: two non-commutative polynomials, which are left and right operands of multiplication respectively. Each polynomial is represented as a LIST of LISTs, and each element in every inner LIST involves only one indeterminate or none (a constant). For example, the polynomial f=2x[2]y[1]x[2]^2-9y[2]x[1]^2x[2]^3+5 is represented as F:=[[2x[1],y[1],x[2]^2], [-9y[2],x[1]^2,x[2]^3], [5]]. The zero polynomial 0 is represented as the empty LIST [].

  • @return: a LIST which represents the polynomial equal to F1*F2.

Example

NC.SetFp(3);
NC.SetX(<quotes>abc</quotes>);
NC.RingEnv();
Coefficient ring : Fp = Z/(3)
Alphabet : abc
Ordering : LLEX
-------------------------------
F1 := [[2,<quotes>a</quotes>],[1,<quotes></quotes>]];
F2 := [[2,<quotes>b</quotes>],[1,<quotes>ba</quotes>]];
NC.Multiply(F1,F2); -- over F3
[[2, <quotes>aba</quotes>], [1, <quotes>ab</quotes>], [1, <quotes>ba</quotes>], [2, <quotes>b</quotes>]]
-------------------------------
NC.Multiply(F2,F1);
[[2, <quotes>baa</quotes>], [2, <quotes>ba</quotes>], [2, <quotes>b</quotes>]]
-------------------------------
NC.Multiply(F1,[]);
[ ]
-------------------------------
NC.Multiply([],F1);
[ ]
-------------------------------
NC.Multiply([],[]);
[ ]
-------------------------------
NC.UnsetFp();
NC.RingEnv();
Coefficient ring : Q
Alphabet : abc
Ordering : LLEX
-------------------------------
NC.Multiply(F1,F2); -- over Q
[[2, <quotes>aba</quotes>], [4, <quotes>ab</quotes>], [1, <quotes>ba</quotes>], [2, <quotes>b</quotes>]]
-------------------------------
NC.Multiply(F2,F1);
[[2, <quotes>baa</quotes>], [5, <quotes>ba</quotes>], [2, <quotes>b</quotes>]]
-------------------------------

See also

Use

NC.SetOrdering

Introduction to CoCoAServer