# Difference between revisions of "ApCoCoA-1:NC.FindPolys"

## NC.FindPolys

Find polynomials with specified indeterminates from a LIST of non-commutative polynomials.

### Syntax

```NC.FindPolys(Polys:LIST, Inds:LIST):LIST
```

### 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 Polys: a LIST of non-commutative polynomials. 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 [].

• @param Inds: a LIST of specified indeterminates.

• @return: a LIST of non-commutative polynomials whose indeterminates are in Inds.

#### Example

```USE QQ[x[1..2],y[1..2]];
F1:= [[2x[1],y[1],x[2]^2], [-9y[2],x[1]^2,x[2]^3]]; -- 2x[1]y[1]x[2]^2-9y[2]x[1]^2x[2]^3
F2:= [[2x[1],x[2]^2], [x[2],x[2]^3],[4]]; -- 2x[1]x[2]^2+x[2]x[2]^3+4
NC.FindPolys([F1,F2],[x[1],x[2]]);

[[[2x[1], x[2]^2], [x[2], x[2]^3], [4]]]
-------------------------------
```