Read Description Set-builder notation { x |1 ≤ x ≤ 3 or x > 5 }

Question

Is it correct to use the ^(and) sign instead of or in the above notation?

Answer 1

using "and," ^ or & would make x a null set, as it's impossible for x to be >5 and <3

"or" means only one of the two conditions needs to be satisfied, either x>5 or 1<x<3, possibly both but in this case not both.

so, no, it would be incorrect to substitute and for or.