For example, you will understand: take 3 as an example, if we require a number greater than 2 or less than 1, then 3 is consistent, because as long as it is consistent with "greater than 2"; Then if we find a number greater than 2 and less than 1 and satisfy "greater than 2 and less than 1", then 3.

No match, and no natural number match.

The symbol of or is ∨, which means "union", and the symbol is ∨, which means "intersection"