Tuple

A tuple is a finite [[Sequence|sequence]].

Two tuples are equal if they have the same length and their corresponding elements are the same:

$$\boxed{(x_1,x_2,...,x_k)=(y_1,y_2,...,y_n)}\text{ means that }k=n\text{ and that }{x}_1=y_1\text{ and so on...}$$