### 2.31.6 Euclidian remainder : `rem`

`rem` takes as arguments two polynomials A and B with coefficients in ℤ/pℤ, where A and B are list polynomials or symbolic polynomials with respect to x or to an optionnal third argument.
`rem` returns the remainder of the euclidian division of A by B in ℤ/pℤ[x].
Input :

`rem((x```^```3+x```^```2+1)%13,(2*x```^```2+4)%13)`

Or :

`rem((x```^```3+x```^```2+1,2*x```^```2+4)%13)`

Output:

`(-2%13)*x+-1%13`

Indeed x3+x2+1=(2x2+4)(x+1/2)+5x−4/4 and −3*4=−6*2=1 mod13.