[chrisseaton]

> looks to me like an editing error; they probably both said "volatile" at one time (or didn't) and the proof failed to update one when updating the other

Isn't it sobering to think that a university slide could have a minor error like that, someone could read it and internalise it as being very important, and then go off and ask interview questions about it (as suggested on the slide!!!!) for the rest of their career!

(Not the fault of the student in this thread, of course.)