In the set theory if A= {A, B} and B= {A, C} does B contain itself?

The expression [math]A=\{A,B\}[/math] is meaningless. It does not define a set [math]A[/math], nor anything else. (EDIT: some people commented that [math]A=\{A,B\}[/math] may be meaningful in v…

Top stories for Long   In the set theory if A= {A, B} and B= {A, C} does B contain itself? Alon Amit, PhD in Mathematics; Mathcircler. • Answered February 4, 2018 The expression [math]A=\{A,B\}[/math] is meaningless. It does not define a set [math]A[/math], nor anything else. (EDIT: some people commented that [math]A=\{A,B\}[/math] may be meaningful in various alternative systems of... Read more » 159 25   Why is sobriety so extremely boring? Christopher Blake, Been traveling or moved around since 5 • Answered October 16 Soooooooooo I am on my second month and I am bored and depressed, and like many have said, the reality of my damaged and lonely life is now visible and obvious. Truthfully,... Read more » 180 77   How can we live in peace while there are atheists? Asked in Divine Atheists • Answered by Try to use Facts, not Hearsay. • Mon Interesting, The Bible is full of text about violence, Murder, Rape, Genocide, War, punishment, The Qur'an is full of text about violence, Murder, Rape, Genocide, War, punish... Read more » 106 114   Why do so many scientists dislike the German theoretical physicist Sabine Hossenfelder? David Kahana, worked at University of Regensburg • Answered September 29 Sabine Hossenfelder was a post-doctoral worker or a graduate student, I'm not quite sure which, at what became Walter Greiner's Institut at the Goethe University, in Frankf... Read more » 931 147   How does sepsis feel? Deborah Jugan, former Attorney • Answered November 4 For me, I felt OK but could not shake the feeling I had something wrong with me. The next day I went to the dentist for a regular appt. but that feeling I had now felt like... Read more » 988 53   How can you prove that √6-√2 > 1 without estimating √6 or √2? Enrico Gregorio, Associate professor in Algebra • Answered March 12, 2023 No estimate necessary. I like to use ? in order to denote a comparison symbol that may be [math]<[/math] or [math]>,[/math] to be determined using only "reversible" steps: [math]\begin{array}{ll} \sqrt{6}-\sqrt{2}\mathrel{?}1 & \text{move the negative term to the right-hand side} \\ \sqrt{6}\mathrel{?}1+\sqrt{2} & \text{square} \\ 6\mathrel{?}1+2\sqrt{2}+2 & \text{leave the radical alone} \\ 3\mathrel{?}2\sqrt{2} & \text{square} \\ 9 \mathrel{?} 8 \end{array}[/math] Now we know that the inequalit... Read more » 162 24   Alberta will soon secede and become the 51st state once Bill 54 passes and a referendum is held (it will pass). Will they be considered a Midwestern or Western state? JoelleEmmily, Researcher (Nuclear Energy, Economics) at Freelancing (1992-present) • Updated November 13 Q: Alberta will soon secede and become the 51st state once Bill 54 passes and a referendum is held (it will pass). Will they be considered a Midwestern or Western state? A: ... Read more » 3.3K 430   Was Mister Rogers ever implicated in any type of scandal? Jean-Marie Valheur, knows a bit about a bit • Answered October 15 Fred Rogers was a great guy, but also a guy born in 1928. He was a religious man, and while open-minded, he knew the power of keeping up appearances. When the actor François... Read more » 5.3K 557   How much fecal matter is held in the human body? Websites like Google are claiming 10-25 pounds, but it seems to be suspected commercial sites that I don't trust. Mike Condron, M.D. Medicine, Meharry Medical College (2004) • Updated March 12, 2018 I handle colons quite a lot in my work (I am a forensic pathologist and have performed over 1600 autopsies). I did a study once of the utility of opening colons to look for... Read more » 20.4K 1.1K   It's almost 2026. Would you choose a Mac or a Windows machine? Franklin Veaux, Technology enthusiast, mad engineer, and tech startup founder. • Answered November 5 As we come to the end of 2025, I think buying a new Windows machine is something of a perverse act of idiocy. The Windows 11 Terms of Use for Windows 11 25H2 specifically gr... Read more » 1.9K 215   I cheated 10 years ago and my spouse doesn't know. Do I have to tell him? Asked in Affairs: The "Other Woman" /The "Other Man" Space • Answered by Richard J. Head • November 8 I have been a lawyer since 1983, and have been handling divorces for 40 years. My law practice has taught me that people disclose past infidelity for three reasons: 1) They... Read more » 4K 536   Why do liberals not want to hear a Republican's point of view? Linda vanDyck, former World traveler, Stewardess, CPA • Updated October 30 I married a Republican. He was a member of the Young Republicans of Philadelphia and had just earned a PhD in Physics from the University of Pennsylvania. I had a high scho... Read more » 8.9K 1.6K Read more in your feed

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