 Let me show you a quick demo. What I'm going to show you is a signal feeding in AND gate. And one signal is going to look like this. And my signal y is going to look like this. So you expect a processed output. So this is 0, I'm sorry, 1, 0, 1, 0, 1. And the output is simply going to be, this is my time axis going this way, is going to be a ANDing of these two signal values like so. What I'm also going to show you is I'm going to superimpose noise on this wire. I'm going to superimpose noise on the wire. And what I want you to observe is the output of this digital gate. The output will stay exactly like this even though I impose noise, the ultimate test. So stay right there. Let's do this demo. Give me a couple seconds. So if you look at the signal up there and I'm imposing, let's have a digital system in a noisy environment, like a lumber yard, for example, or chopping a bunch of trees in my backyard, building digital systems on the side. And if I have my buddies running up chainsaws, super imposing noise on my second input, but look at the output. And just to know that, show that I'm not bluffing here, what I'll do is I'll pass the noise through and make the noise larger. And you'll notice that when the noise begins to surpass the noise margins, the output begins to go berserk. Watch. Can you increase it gradually? So notice that as I put in a lot more noise, then the output begins to go berserk. But as long as my input is within the noise margin, my output stays perfectly stable. So that's the intro to digital systems. You'll see numbers in recitation. And we'll see you in lecture on Tuesday.