28. Define the set X CZ+ recursively as follows: 1) 3 € X; and 2) If a, b e X, then a + b € X. Prove that X = {3k|k € Z+
Posted: Tue Jul 12, 2022 12:06 pm
28. Define the set X CZ+ recursively as follows: 1) 3 € X; and 2) If a, b e X, then a + b € X. Prove that X = {3k|k € Z+}, the set of all positive integers di- visible by 3.