`ntogf2n'
---------

ntogf2n(M)
     :: Converts a non-negative integer into an element of GF(2^N).

RETURN
     element of GF(2^N)

M
     non-negative integer

   * Let M be a non-negative integer.  M has the binary representation
     M=M0+M1*2+...+MK*2^k.  This function returns an element of
     GF(2^N) = GF(2)[t]/(g(t)), M0+M1*t+...+MK*t^k mod g(t).

   * Apply `simp_ff()' to reduce the result.

     [1] setmod_ff(x^30+x+1);
     x^30+x+1
     [2] N=ntogf2n(2^100);
     (@^100)
     [3] simp_ff(N);
     (@^13+@^12+@^11+@^10)

References
     *Note `gf2nton': gf2nton

