Tupple Relational Calculus is a non-procedural query language unlike relational algebra. Tupple Calculus provides only the description of the query but it does not provide the methods to solve it. Thus, it explains what to do but not how to do.
In Tupple Calculus, a query is expressed as
where t = resulting tupples,
P(t) = known as Predicate and these are the conditions that are used to fetch t
Thus, it generates set of all tupples t, such that Predicate P(t) is true for t.
P(t) may have various conditions logically combined with OR (∨), AND (∧), NOT(¬).
It also uses quantifiers:
∃ t ∈ r (Q(t)) = ”there exists” a tuple in t in relation r such that predicate Q(t) is true.
∀ t ∈ r (Q(t)) = Q(t) is true “for all” tuples in relation r.