code: function greaterShift(x, y, shift) {
    var i, kx=x.length, ky=y.length;
    k=((kx+shift)<ky) ? (kx+shift) : ky;
    for (i=ky-1-shift; i<kx && i>=0; i++)
      if (x[i]>0)
        return 1; //if there are nonzeros in x to the left of the first column of y, then x is bigger
    for (i=kx-1+shift; i<ky; i++)
      if (y[i]>0)
        return 0; //if there are nonzeros in y to the left of the first column of x, then x is not bigger
    for (i=k-1; i>=shift; i--)
      if      (x[i-shift]>y[i]) return 1;
      else if (x[i-shift]<y[i]) return 0;
    return 0;
  }
docs: is (x << (shift*bpe)) > y? x and y are nonnegative bigInts shift is a nonnegative integer