One or more of A, B, C, [and, or, and/or] D?

Solution 1:

They do actually have different meanings, but it's very subtle..

"One or more of A, B, C and D" means that of the sets a, b, c and d, you have one of (or more) the options available, with the set A, B, C and D inclusive. Possible sets include any combination of A, B, C, D, but not multiples of any of the set (So, for example, you could pick B, C, D as your set, but not B, B, C).

"One or more of A, B, C or D" means you have the option to pick "one or more of" the defined choices, but not more than one of the set. So you could pick as many of A, B, C, or D that you desire, but you may not mix (A set of A, A, A is acceptable, but a set of A, A, B is not).

The reason for this is that "or" is an exclusive operator. It allows for any choice to be made, but only ONE choice. "And", on the other hand, is inclusive, and allows any choice to be made within the set. So "one or more" of the set "A, B, C and D" allows for any choice to be made on which letter is included, but does NOT allow for multiples of the set.

The last case, "One or more of the set 'A, B, C and/or D'" actually has a hidden operative. The "/" symbol conjoins the two operators, so it allows for BOTH operators to apply. In other words, it removes the limtation of either operator and allows for multiples of each choice AND more than one choice.