ELI5: Explain Like I'm 5

Zhegalkin polynomial

Okay kiddo, let me explain to you what a zhegalkin polynomial is. You know how you can add and multiply numbers, right? Well, a zhegalkin polynomial is a special way of adding and multiplying "variables" that helps us simplify boolean logic expressions.

Let's say you have two variables: A and B. A zhegalkin polynomial is just a fancy way of writing out all the possible combinations of A and B and then adding and multiplying them together. So for example, we could write out all the possible combinations of A and B like this:

(A AND B) OR (A AND NOT B) OR (NOT A AND B) OR (NOT A AND NOT B)

Now, if we want to simplify this expression, we can use the zhegalkin polynomial. We start by assigning a "binary number" to each combination of A and B. For example, we could assign "00" to (NOT A AND NOT B), "01" to (NOT A AND B), "10" to (A AND NOT B), and "11" to (A AND B).

Then, we write out the zhegalkin polynomial by adding and multiplying these binary numbers together. For our example expression, the zhegalkin polynomial would be:

f(A,B) = 0 + B + A + (AB)

Don't worry if this looks confusing, we're almost done explaining. The cool thing about the zhegalkin polynomial is that we can use it to simplify boolean expressions. For example, we could rewrite the original expression as:

f(A,B) = (A XOR B)

This means that the zhegalkin polynomial helps us simplify boolean expressions into simpler forms that are easier to understand and work with.

So in summary, a zhegalkin polynomial is a way of adding and multiplying variables together to simplify boolean logic expressions. It uses binary numbers to represent combinations of variables, and can be used to make boolean expressions easier to understand and work with.