Function: mfderiv
Section: modular_forms
C-Name: mfderiv
Prototype: GD1,L,
Help: mfderiv(F,{m=1}): m-th formal derivative of the power series
 corresponding to the generalized modular form F, with respect to the
 differential operator q.d/dq (default m=1).
Doc:  $m$-th formal derivative of the power series corresponding to
 the generalized modular form $F$, with respect to the differential operator
 $qd/dq$ (default $m=1$).
 \bprog
 ? D=mfDelta();
 ? mfcoefs(D, 4)
 %2 = [0, 1, -24, 252, -1472]
 ? mfcoefs(mfderiv(D), 4)
 %3 = [0, 1, -48, 756, -5888]
 @eprog
