The study was carried out up to visit 11 under the name of
X1,
whereas all later visits were carried out under a different name,
X2.
In the above sentence, does V11 belong to X1 or X2? I want the sentence to mean that V11 was included in X1, how should the sentence be then?
Best Answer
People do use the term in both ways (rightly or wrongly), so it is best to examine the context, to help you decide what is meant.
However, without additional information from the context, I would say that the correct meaning is up to but not including.
To express inclusion of the upper boundary, you can use up through instead of up to.
(And I agree with others that there are less ambiguous ways to express ranges and inclusion/exclusion of their limits.)