Mar 18, 2011 · Other symbols I have seen used for "is defined to be equal to" are three horizontal lines instead of two, and $=$ with either a triangle or "def" written directly above it. I have seen variants of …

Jan 16, 2016 · I was reading a paper about well-orderings and this came up: Suppose (E, ≤) and (F, ≼) are isomorphic well-orderings. Then there exists a unique isomorphism for (E, ≤) to (F, ≼). I've been …

Dec 22, 2020 · I have encountered this when referencing subsets and vector subspaces. For example, T ⊊ span(S) should mean that T is smaller than span(S)--at least from what I've gathered. Is ⊊ a sort of …

Mar 1, 2026 · This page is from Measure and category by John C. Oxtoby page 20. What is the meaning of this symbol? I added a red line under it. There is no definition of this symbol in this book, so I couldn't

Jun 25, 2014 · I have started seeing the "∈" symbol in math. What exactly does it mean? I have tried googling it but google takes the symbol out of the search.

Nov 7, 2015 · What exactly does $\\ll$ mean? I am familiar that this symbol means much less than. ...but what exactly does "much less than" mean? (Or the corollary, $\\gg$) On Wikipedia, the example they …

Jul 28, 2021 · What do the less-than and greater-than symbols right next to each other mean? Does it mean either less than or greater than? In other words, not equal? I am trying to understand a book …

May 6, 2015 · The meaning of various equality symbols Ask Question Asked 10 years, 10 months ago Modified 9 years, 10 months ago

Jul 22, 2010 · In summary: The interplay of meaning and axiomatic machine mathematics, captured by the difference between $\models$ and $\vdash$, is a subtle and interesting thing.

Usually you see mathematicians start $\mathbb {N}$ at $1$, while computer scientists and physicists start at $0$, but it all depends on which is more convenient at the time.