# ApCoCoA-1:NC.CToCoCoAL

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

## NC.CToCoCoAL

Convert a polynomial in a non-commutative polynomial ring from the C format to the CoCoAL format.

### Syntax

NC.CToCoCoAL(F:LIST):INT

### Description

Please set non-commutative polynomial ring (via the command Use) before calling this function. For more information, please check the relevant commands and functions.

@param

*F*: a non-commutative polynomial in the C format. Every polynomial is represented as a LIST of LISTs, and each inner LIST contains a coefficient and a LIST of indices of indeterminates. For instance, assume that the working ring is QQ[x[1..2],y[1..2]], then indeterminates`x[1],x[2],y[1],y[2]`are indexed by`1,2,3,4`, respectively. Thus the polynomial`f=2x[2]y[1]x[2]^2-9y[2]x[1]^2x[2]^3+5`is represented as [[2, [1, 3, 2, 2]], [-9, [4, 1, 1, 2, 2, 2]], [5, []]]. The zero polynomial`0`is represented as the empty LIST [].@return: a LIST, which is the CoCoAL format of the polynomial F.

#### Example

USE QQ[x[1..2],y[1..2]]; F:= [[2, [1, 3, 2, 2]], [-9, [4, 1, 1, 2, 2, 2]], [5, []]]; NC.CToCoCoAL(F); [[2x[1], y[1], x[2]^2], [-9y[2], x[1]^2, x[2]^3], [5]] -------------------------------

### See also