CDEF Question

[DeathDream]

Hey
I Want to do this in CDEF:

if (a&c = Unknown)
return "Something"

"this means if both of them are "unknown" do something"

for doing this, i am using below code right now but i need a better way:

a,UN,1,0,IF,c,UN,1,0,IF,+,2,EQ,"Something"

How can i do it?