# ApCoCoA-1:Weyl.WMulByMonom

From ApCoCoAWiki

This article is about a function from ApCoCoA-1. |

## Weyl.WMulByMonom

Computes the product `M*F` of a Weyl monomial `M` and a Weyl polynomial `F` in normal form.

### Syntax

Weyl.WMulByMonom(M:POLY,F:POLY):POLY

### Description

This function multiplies a Weyl monomial `M` with a polynomial `F` and returns `M*F` as a Weyl polynomial in normal form.

@param

*M*A Weyl monomial.@param

*F*A Weyl polynomial.@return The product

`M*F`, a Weyl polynomial in normal form.

*Note:* Monomials and polynomials that are not in normal form should be first converted into normal form using Weyl.WNormalForm, otherwise you may get unexpected results.

#### Example

A1::=QQ[x,d]; --Define appropriate ring Use A1; M:=x^3d^4; F:=x^3+d^3+3xd+5; Weyl.WMulByMonom(M,F); x^6d^4 + x^3d^7 + 3x^4d^5 + 12x^5d^3 + 17x^3d^4 + 36x^4d^2 + 24x^3d ------------------------------- Weyl.WMulByMonom(F,M); -- note the input ERROR: 1st parameter should be a Monomial! CONTEXT: Error(<quotes>1st parameter should be a Monomial!</quotes>) -------------------------------

### See also