I'm trying to get $\displaystyle f(a,b,c) = (a'b)'(a+c)'+a(c+b')+ab'(c+a')$ into DNF and was wondering what happens when I get terms that don't have all three boolean algebras in them or two of the same in a group?

Solving, I get:

$\displaystyle (a+b')(a'c')+(ac+ab')+(ab'c+ab'a')$

$\displaystyle aa'c'+b'a'c'+ac+ab'+ab'c+ab'a'$

Do I just drop everything other than $\displaystyle b'a'c'$ and $\displaystyle ab'c$?