In my text book I saw the sentence: If a request is made to a web service, then the response will be returned within 5 seconds or the service is under DoS attack.
I cannot understand the usage of or in this sentence. Is it an exclusive or meaning that if the response will be returned within 5 seconds then there is no possibility of a DoS attack? Or does it just mean that if no response will be returned in 5 seconds, the service is under DoS attack. I will appreciate any help on understanding this sentence.-
1I think it can be inferred from the sentence that " if the response will not be given within 5 seconds, then you can understand that the service is under Dos attack"– MrtCommented Oct 24, 2018 at 3:22
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They should have used 'unless' instead of 'or'.– amICommented Oct 24, 2018 at 4:28
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I think it should be "otherwise".– user3169Commented Oct 24, 2018 at 5:51
1 Answer
I don't think it's an exclusive or, because you can be under attack and still get a response within 5 seconds. I think what you have here is an inclusive disjunction, which you can read about here.
A = The response will be returned within 5 seconds.
B = The service is under DoS attack.
If A is false, then B must be true. If A is true, B can be either true or false.
So if you get a response within 5 seconds, you don't know if the service is under attack or not. Generally speaking, you can assume it's inclusive disjunction unless you're told it's the exclusive-or.