My name is John. I am a 68 year old retiree who enjoys working with high school students to improve their algebra and geometry skills. I have been doing on-line tutoring for 4 years and believe I’ve helped several students improve their grades while also keeping my own cognitive skills refreshed in retirement. (read more)
...It has also been shown that if R on A is antisymmetric, R n R-1 ? {(a, a): a ? A}. Therefore, a relation R on a set A is antisymmetric if and only if R n R-1 ? {(a, a): a ? A}.
Given that A and B are sets, (A - B) n (B - A) = { }.
Let A and B be sets. Suppose, for the sake of contradict... (read more)