 All right, so here's what we're talking about. Notation, all this fun stuff, the SD, the SRs, the Sdeltas, and all that joyous, lovely stuff that tends to kind of throw people through it once in a while. I cover it in various places, but I don't have a really good single lecture on notation and behavior analysis, so here it is. All right, so the first thing's first. We have the three-term contingency. That's the basic pieces, right? So the notation we use for that is simple. An SD is the first term. That stands for a discriminative stimulus, or stimulus that discriminates how we want to look at it. So it's written with a superscript, right? So S with a D up in the superscript, right? Then the second term and the three-term contingency is an R, or a response. The third term is the S, and it's something else, right? There's a lot of something else, so we'll start with the first one, the easiest one, which is SR, right? SR means a stimulus that reinforces. We can talk about the issues with that later on. If you guys want to talk about premac pencil pole and stimuli and more actions and all that stuff, that's a different topic, okay? So an SR is a stimulus that reinforces. Now as you know, we have two types of reinforcement. So there are two different notations for that. There's SR plus and there's SR minus. The first one, SR plus, is obviously positive reinforcement, and the second one is negative reinforcement, which leads us to another consequence notation that exists, which is SP, or a stimulus that punishes. So then you would have an SP plus and an SP minus. Positive punishment, negative punishment. There's also this other thing called, I'm sorry, so that's the notation for that consequence piece, right? So the third term and the three-term contingency. But let's move back to the first term, because there's some variations on the SD that we want to talk about. An SD signals to the organism that a reinforcer is available in that context at that time for a particular response. That's what the SD signals. So the SD is about signaling a reinforcer. You could also have an SP, or sorry, I'm going to try that again. You have an SDP, right? A discriminative stimulus that signals that punishment is coming. You could have that. You could also have this cool thing called an SDALTA, which basically signals that extinction is going to happen. In other words, there are no reinforcers available. That's what an SDALTA signals. SDALTA signals no reinforcer. SDP signals that there's a punisher coming. SD signals that there's reinforcement available. Okay? And so those are your core pieces. Now let's add in another one, motivating operations. MOs, there's two types, right? An EO and an AO. And then there's more breakdowns than that, right? You get the CMEOs and all that stuff. So you get all those other ones, right? So we're just going to call it an MO to make it easy, right? MOs typically come in the three-term contingency that plays before the SD. So it typically reads MO, SD, or SR. But in reality, a motivating operation affects the value of a reinforcer. It doesn't affect the value of the discriminative stimulus. So in reality, it's like it kind of sits below it, but concurrent, it's weird. It's hard to talk about this stuff because it makes us think that it's this weird chain and it always happens in that order. Sometimes things kind of happen concurrently. And that's kind of what the issue is with the motivating operation. It is something that has happened before the reinforcer is delivered. So we have to put it somewhere in there. So we put it in front of everything. But it's not like you go MO happens, and then an SD, then an R, and an SR. The MO could have happened months ago. Could be happening concurrently. But it doesn't affect the SD. It affects the reinforcer. So it is what drives the, it changes the value of that reinforcer. So hopefully that clarifies a couple of issues. And I hope that my drawing here makes some sense. And I will talk to you all soon. Take care.