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 5, 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 …

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 scouri...

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

Apr 28, 2012 · After looking at the Wikipedia article on topological space, I still cannot grasp intuitively what topological space is. For example, if we are to define topology on real numbers, can there be …

May 25, 2025 · What is the standard definition of completeness? From what I have researched I have come across two different definitions: A set of formulas $\\Gamma$ is complete iff for all formulas …

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

I have read that an infinitesimal is very small, it is unthinkably small but I am not quite comfortable with with its applications. My first question is that is an infinitesimal a stationary value?...

Jun 22, 2023 · When someone uses the phrase "percent increase" what does that mean? For example, if something took $4$ seconds before and now it takes $1$ second, would that be a …

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 …