How to match both k and -k with sets?

[veretin]

Hi!

I want to match both +k and -k in one line with set restriction.
Is it possible? In this case "k" is a vector

v k,k1,k2, p, q;
set kk: k, k1, k2;
c A;

g ff1 = A(k);
g ff2 = A(-k);

id A(k?kk) = 0;
id A(-k?kk) = 0;

print;
.end

We need 2 lines to capture both. Can we do this in one line?
Regards,
OVeretin

[tueda]

Seems to work:

V k,k1,k2,k3,k4,p;
Set kk: k1,k2,k4,-k1,-k3,-k4;
CF f;
L F =
#do k={k1,k2,k3,k4,-k1,-k2,-k3,-k4,p}
  + f(`k')
#enddo
;
id f(k?kk) = 0;
P +s;
.end

   F =
       + f(k3)
       + f(p)
       + f(-k2)
      ;