Derivative( f )
Let f be a Laurent polynomial (..., f_{-1}, f_0, f_1, ...). Then
Derivative
returns the polynomial g = (..., g_{i-1} = i* f_i, ... ).
gap> x := Indeterminate(Rationals);; x.name := "x";; gap> Derivative( x^10 + x^-11 ); 10*x^9 - 11*x^(-12) gap> y := Indeterminate(GF(5));; y.name := "y";; gap> Derivative( y^10 + y^-11 ); Z(5)^2*y^(-12)
GAP 3.4.4