I solved it on my own. :)
C1:
count(c2, d1:0(l(1,0)), m1)
C2:
sum(all, 0, m1)
(This is necessary because I also want to see it over regions)
C3:
if sum(c1, 0, 0) <> sum(c1, -1, 0, 0) then sum(all, 0, m1) else if sum(c1, 0, 0) <> sum(c1, -2, 0, 0) then sum(all, 0, m1) else if sum(c1, 0, 0) <> sum(c1, -3, 0, 0) then sum(all, 0, m1) else if sum(c1, 0, 0) <> sum(c1, -4, 0, 0) then sum(all, 0, m1) else if sum(c1, 0, 0) <> sum(c1, -5, 0, 0) then sum(all, 0, m1) else 0
And then:
Visibility Agent on c3 = 0