Express each of these system specifications ing predicates, quantifiers, and logical connectives where C(f) is "File f can be closed" O(d) is "Directory d can be opened" E(j) is "System error j has been detected" W(u) is "er u received a warning message" L(u) is "er u is logged in" Y is "the file system can be backed up" V is "video on demand can be delivered" s is the connection speed in megabits per second. m is the amount of memory available in megabyte When there is less than 30 megabytes free on the hard disk, a warning message is sent to all ers.
a. ∀uW(u) → (m < 30)
b. (m < 30) → ∀uW(u)
c. (m > 30) → ∀uW(u)
d. (m < 30)