LaurentPolynomialRing( R )
LaurentPolynomialRing returns the ring of all Laurent polynomials over
a field R or ring-with-one R.
gap> f2 := GF(2);;
gap> R := LaurentPolynomialRing( f2 );
LaurentPolynomialRing( GF(2) )
gap> Z(2) in R;
false
gap> Polynomial( f2, [Z(2),Z(2)] ) in R;
true
gap> Polynomial( GF(4), [Z(2),Z(2)] ) in R;
false
gap> Indeterminate(f2)^-1 in R;
true
GAP 3.4.4