- #1

jaqueh

- 57

- 0

## Homework Statement

Use the berstein theorem to show: if A[itex]\subseteq[/itex]ℝ and there exists an open interval (a,b) such that (a,b)[itex]\subseteq[/itex]A, then the cardinal number of A=ℂ

## Homework Equations

The theorem states that if card(A)≤card(B) and card(B)≤card(A), then card(A)=card(B)

## The Attempt at a Solution

I don't know what is relevant and what the open interval (a,b) implies. I know that (a,b) is a subset of ℝ and its equivalent to ℂ, but i don't know if I am supposed to prove that or what I am supposed to do at all