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 …

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 …

May 20, 2018 · $\equiv$ and similar variations are a generic symbols used to notate an equivalence relation. $=$ is the specific equivalence relation "equals" that we are used to with sets and natural …

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

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 …

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 …

May 6, 2015 · Maybe instead of handling your example, because the context is not always relevant, let's look at possible groupings of the symbols. Equality $=$ is usually used for equality. $\equiv$ is …

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 …

Jul 1, 2022 · Textbook Notation: Meaning of cf. [closed] Ask Question Asked 3 years, 8 months ago Modified 3 years, 8 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.