Suppose we have a relation Student(Name,Marks) with 2 tuples (a,100) and (a,100). Now if I have a expression like :- { t.Name, t.Marks | Student(t) and t.Marks=100) . Then will I get both tuples or only a single tuple?
I know that in relation algebra we use project operator which removes duplicates .
I couldn't find a reference which says that in tuple relational calculus we don't consider duplicates.
Relations are defined as sets, not tables/bags. That means relations don't have multiple identical tuples.
Representing the same number/value/fact twice doesn't mean I represented two different numbers/values/facts.