`gf2ntop'
---------

gf2ntop(M[,V])
     :: GF(2^n) $B$N85$rB?9`<0$KJQ49(B

RETURN
     $B0lJQ?tB?9`<0(B

M
     GF(2^n) $B$N85(B

V
     $BITDj85(B

   * M $B$rI=$9B?9`<0$r(B, $B@0?t78?t$NB?9`<0%*%V%8%'%/%H$H$7$FJV$9(B.

   * V $B$N;XDj$,$J$$>l9g(B, $BD>A0$N(B `ptogf2n()' $B8F$S=P$7(B $B$K$*$1$k0z?t$NJQ?t(B
     ($B%G%U%)%k%H$O(B `x'), $B;XDj$,$"$k>l9g$K$O(B
     $B;XDj$5$l$?ITDj85$rJQ?t$H$9$kB?9`<0$rJV$9(B.

     [1] setmod_ff(x^30+x+1);
     x^30+x+1
     [2] N=simp_ff(gf2ntop(2^100));
     (@^13+@^12+@^11+@^10)
     [5] gf2ntop(N);
     [207] gf2ntop(N);
     x^13+x^12+x^11+x^10
     [208] gf2ntop(N,t);
     t^13+t^12+t^11+t^10

$B;2>H(B
     *Note `ptogf2n': ptogf2n

