# ApCoCoA-1:Weyl.WMulByMonom

From ApCoCoAWiki

## Weyl.WMulByMonom

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

### Syntax

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

### Description

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

#### 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("1st parameter should be a Monomial!") -------------------------------

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

### See also