Advanced 3: Replace Parts of a Lunchbox

Let me give you a hint to reproduce the “Repeat” feature using a lunchbox.

Let’s take a look at this lunchbox:

This looks really complicated…

Now, here’s a question: What happens when you run it?

Well… there’s no way I can figure it out in my head. It’s too complicated.

I figured it out! I think the result will be a lunchbox that can be converted to .

Correct. Saya, You’re exactly right!

What? How is it possible that you figured it out so quickly?

Saya, did you solve it all in your head?

Not really. Actually, I used a trick. Let me explain.

First: Take a look at the top section.

Oh! The top section is actually a lunchbox that can be converted to .

Yes. So we’ll replace this section with .

Second: Take a look at the middle-right section.

The middle-right section is actually a lunchbox that can be converted to .

Yes. So we’ll replace this section with .

I see…

Now, take a look at this section.

This looks like Saya’s lunchbox that can reproduce the “Plus 1” feature .

Exactly. So we’ll replace this with .

Hmm… it’s getting much simpler.

Finally, take a look at the bottom-right section.

Oh! This looks exactly like the one we saw on the last page: a lunchbox that reproduces the “Conditional” feature .

Exactly. So we’ll replace it with the “Conditional” feature .

Here’s how we’re going to replace it:

After the replacement, it’ll look like this:

Wow, it’s much simpler now!

Let’s run it. Press Run !

From here, it’s simple.

• Because is , which is not zero…
• The result will be what’s in , which is .

Press Run !

See, the final result is .

Hmm… You’re right.

But… isn’t that cheating?

Saya’s method was to replace each section with the corresponding mathbox features…