In mathematical notation, what are the usage differences between the various approximately-equal signs "≈", "≃", and "≅"? The Unicode standard lists all of them inside the Mathematical Operators B...
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 ≤ or <...
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 that says th...
Whats the meaning of this symbol? Its a three dot symbol: ∴ I read a book, im could not find any definition of this symbol. This is about continuum property of the natural numbers and the archimed...
Edit: to simply say, what I really need is somehow formal or intuitive concept of topology and topological space that would allow me to grasp the meaning of topology and topological space. Thanks.
It's an abbreviation of quod erat demonstrandum, which is the Latin translation of a Greek phrase meaning "which had to be proven". To the ancient Greeks, a proof wasn't complete unless the last sentence in your proof was basically the statement of the theorem.
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.
