The orange is selected if and only if the apple or grape is/are selected.
May I ask whether using is or are is correct in the above sentence?
The orange is selected if and only if the apple or grape is/are selected.
May I ask whether using is or are is correct in the above sentence?
An "apple or grape" is only one thing, so you would use is here. If the list is mixed, you would use the plural: "if apples or a grape are selected" is correct. (Note also that it's necessary to use the a here, since we're mixing singular and plural list members.) Also, "if an apple and grape are selected" is correct.
XORrather than logicalOR, in other words or in the sense that excludes and. If I say that someone took an apple or a grape, I don't mean that he took both. If he took both, he took an apple and a grape. Can you give me an example of a sentence where "or" refers to logicalORand uses the plural? I can't think.of one, and your "A or B are" sounds strange to me. – BobRodes Feb 24 '21 at 23:48