Yes, the set $B$ can be written as:

$B = \{ x \mid x \text{ is a prime number and } x < 8 \}$

To clarify, the set consists of prime numbers that are less than 8. The prime numbers less than 8 are:

$2, 3, 5, 7$

So, the set $B$ can also be expressed explicitly as:

$B = \{ 2, 3, 5, 7 \}$

If you are referring to a particular context where this set is defined, it could vary, but based on the given condition, this is the correct interpretation.

Would you like further details or have any questions about prime numbers or set notation?

Related Questions:

1. What are prime numbers and how do we identify them?
2. How do we represent sets using set-builder notation?
3. What is the importance of prime numbers in number theory?
4. Can a prime number be negative, and why or why not?
5. How does set notation change for different types of sets (e.g., infinite, finite)?

Tip: When using set-builder notation, ensure that the condition inside the curly braces properly defines the elements of the set.