 Okay, so these are the isomeric xyleanes. You can see they're all three disubstituted benzene rings, right, two methyl groups. So they're all isomers of each other, right? So, structural isomers. If you want to look, though, you all, you should notice that, of course, they're all different compounds, right? Because the structure is different. That's the structural isomers, right? So these disubstituted benzene, they all have different names. They're all called, in fact, this one, since it's two methyl groups, they're all called xyleanes, okay? But the position of the two substituted groups on the ring describes more of the name, okay? So the name, if you've got the substituents in the one, two position, it's called ortho. So this would be ortho xyleane. If you've got it in the one, two, three position, it's called meta. So this is meta xyleane. Another, you could also call this o xyleane or m xyleane. And if you've got them across from each other in the one, four position, it's called that para, yeah. So you could call it para xyleane or even, but you'll usually see them italicized, ortho meta para. So disubstituted, you wanna remember ortho meta para. Okay, anybody got any questions on that?