Date: Tuesday, 23rd October 2001 23:06 Central Daylight Time From: Mark Jacobson To: 810-080-01@uni.edu, 810-080-02@uni.edu Subject: Empty sets and Monday quiz... Hi Discrete Structures students, Whereas the grader will not be able to get the HW #5 graded so it can be turned back tommorrow, be it hereby declared that the Friday quiz will be held on Monday instead. (That no longer makes it a Friday quiz, does it!). Quiz on Monday, October 29th. I also here there is a tough, tough Java programming assignment due on Friday, so that is another reason not to have a quiz on Friday. Here is some more information on sets and empty sets.... empty set = { } Set containing the empty set is NOT EMPTY. { {} } The empty set { } has 0 elements or members. The set { {} } contains ONE element. The {} is a member of { {} }. {} is an element of { {} }. The {} has no elements. The set { {} } has cardinality or size 1. The set { } has size 0. If you see anything inside the {}, then you are seeing a set that is NOT EMPTY. { } <------- The empty set, is empty. { {} } <------- This set contains something, the {} is one of its members or elements. Mark P.S. There is a stapler in Wright 110/112 lab. The stapler is on the cart that has the telephone. The math and the computer science office also have staplers. HW #6 should be stapled.