There are two points at -2 and 1 on the number line. Write the set of numbers represented on the number line in interval notation.

Please directly answer the question and provide the final value, e.g., 1, 2.5, 300.
Question: There are two points at -2 and 1 on the number line. Write the set of numbers represented on the number line in interval notation.

Please first conduct reasoning, and then answer the question and provide the final value, e.g., 1, 2.5, 300, at the end.
Question: There are two points at -2 and 1 on the number line. Write the set of numbers represented on the number line in interval notation.
