verification of difference of sets

Question

New to this, would this be correct?

If we have $A = {1,2,3}, B = Z^{+}, C = [1,\infty)$

Where $C = {x \in R : x \geq} 1 $

Then $B-A $ would be:

$(x \in Z^{+}, x>3) $

and $C-A$ would be:

$(x \in R, x>3)$

Answer 1

$C-A$ should include some elements that are less than $3$ as well. For example $1.5$ is in $C-A$. It has not been excluded.

$$C-A=(1, \infty) \setminus \{2,3\}=(1,2) \cup (2,3) \cup (3, \infty).$$