00:01
Okay, so for part a, we have, when there is less than 30 megabytes free on the hard disk, a warning message is sent to all users.
00:09
Okay.
00:11
So let's let p of x be that x has less than 30 megabytes free.
00:20
And let's let q of x be warning message is sent.
00:29
Let's actually make this y sent to y.
00:32
Okay, so we have that, what was our statement? when there's less than 30 megabytes free on the hard disk, a warning message is sent to all users.
00:41
So there exists some x, such that when x is, when p of x, or x is less than 30, then this implies that all users get a warning message for all y, q of y happens.
00:58
Okay, now for part b, we have that no director's, no directories in the file system can be opened and no files can be closed when system errors.
01:08
Have been detected.
01:09
So let's let r of x be that directory x cannot be opened.
01:27
And let's the s of y, the file y can be closed.
01:35
Okay, we said that no directories in the file system can be opened, and no files can be closed when the system errors have been detected.
01:50
Okay, so let's let's let's see, we actually need one more...