# introduction to set theory

#### Yeison

I have some trouble when proving the existence of set. In this particular case, I would like to have some help as to how to prove that Seq(A) exists. Where Seq(A) denotes the set of all finite sequences of elements of A. I am using as textbook "Introduction to set theory" from Hrbacek.

I would appreciate any help.

#### chiro

MHF Helper
Hey Yeison.

Can you represent the sequence in terms of unions of set elements and show that a set (even that which is ordered) exists by taking unions and ordering if necessary?

#### HallsofIvy

MHF Helper
Exactly what does it mean for a set to "exist"?