To use the wireless network in the airport you must pay the daily fee unless you are a subscriber to the service. Express your answer in terms of
w: “You can use the wireless network in the airport,”
d: “You pay the daily fee,”
and
s: “You are a subscriber to the service.”
So here it should be w -> (d v s) (If must is considered the same as necessary (conditional)) However, Is it? Is must the same as conditional or is it comparable to if and only if?
It is only conditional; i.e. to use the network, it is necessary to pay the fee or subscribe. However, this may not be sufficient as one might also need to set up some sort of account or whatever the case may be.