### 2.25.4 Euclidean remainder : `rem`

`rem` returns the euclidean remainder between two polynomials (decreasing power division). If the polynomials are represented as expressions, the variable may be specified as a third argument.
Input :

`rem(x```^```3-1,x```^```2-1)`

Output :

`x-1`

To have the remainder of x2+2x+4 by x2+x+2 we can also input :

`rem([1,2,4],[1,1,2])`

Output :

`[1,2]`

i.e. le polynomial x+2.