docs: function ecp_proj(R, N, p, l) {
  	var x = N[0], y = N[1], z = N[2];
  	var xr = R[0], yr = R[1], zr = R[2];
  	var t0 = _ecp_t0, t1 = _ecp_t1, t2 = _ecp_t2;
  	fp_mul(t2, t0, fp_sqr(t1, fp_inv(t0, z, p, l), p, l), p, l);
  	fp_mul(xr, x, t1, p, l);
  	fp_mul(yr, y, t2, p, l);
  	mpn_zero(zr, l), zr[0] = 1;
  	return R;
  }