3
$\begingroup$

The Dual of a Boolean function $F(x_1, x_2, ..., x_n)$, written as $F^D$ is the same expression as that of $F$ with $+$ and $.$ swapped. $F$ is said to be self dual if $$F=F^D$$

How can we count total number of self dual function with $n$ Boolean variables.

I know For $n$ variables total $2^n$ minterms or maxterms are possible and any boolean function can be expressed as combination of minterms or maxterms. But what else is required to count all self dual functions of $n$ variable.

$\endgroup$
1
$\begingroup$

Using de Morgan's laws, we get a more useful characterization of self-dual functions: those are functions satisfying $\lnot F(x_1,\ldots,x_n) = F(\lnot x_1,\ldots,\lnot x_n)$. Suppose that you knew the value of a self-dual function on all inputs in which $x_1$ is false. Can you recover the rest of $F$? Can you deduce the number of self-dual functions?

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.