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13h
comment Prove that $\mathcal B(\mathbb R)\times \mathcal B(\mathbb R)\subseteq \mathcal B (\mathbb R^2)$
I don't quite understand your notation. What is $\mathcal D$? And what does $B(0, n)$ mean?
16h
comment How do irrational numbers lie on the number line?
@anorton That should be an answer.
2d
revised Are “almost all” graphs hamiltonian?
added 3 characters in body
Oct
19
comment The set $\mathbb{Z}$ is totally ordered
How are you defining $-$? I suppose $b-a$ means "the unique $x\in\mathbb N$, if it exists, such that $a+x=b$". In that case, it would be equivalent and probably simpler to define $a\leq b$ as $\exists x\in\mathbb N\ a+x=b$.
Oct
19
comment proving a sequence is increasing defined by a recurrence relation.
To be clear, you want to show that the sequence $b_n$ is increasing. It's meaningless to say a relation is increasing.
Oct
18
comment How to formalize proofs
You're implicitly assuming that if you increase either $a$ or $b$, then $a/b + b/a$ will increase (or at least not decrease). You need to prove that (assuming it's even true).
Oct
18
comment Prove that $\mathcal B(\mathbb R)\times \mathcal B(\mathbb R)\subseteq \mathcal B (\mathbb R^2)$
@TomekKania Wait, are you sure? I thought it meant Cartesian product. The exercice doesn't specify.
Oct
18
comment Prove that $\mathcal B(\mathbb R)\times \mathcal B(\mathbb R)\subseteq \mathcal B (\mathbb R^2)$
@saz Yes.${{}}$
Oct
18
asked Prove that $\mathcal B(\mathbb R)\times \mathcal B(\mathbb R)\subseteq \mathcal B (\mathbb R^2)$
Oct
18
revised Is there an introductory book on Genetic Sequencing Theory for mathematicians?
edited tags
Oct
18
answered Why isn't area under curve from 0 to infinity of $\frac{1}{x^2}$ equal to 3?
Oct
17
answered “Introducing something extra”
Oct
13
comment What is a “formal definition” of a set?
Could you provide more context? What is the exact formulation of the question?
Oct
12
answered Adjusting weight of a body of water by substituting part of it with a lighter liquid
Oct
10
accepted Is there a geometrical definition of a tangent line?
Oct
8
comment Is there a geometrical definition of a tangent line?
Could you clarify what you mean by "one direction" and "other direction"?
Oct
5
asked Is there a geometrical definition of a tangent line?
Oct
4
reviewed Approve suggested edit on Prove all multiples of $U$ contain all the digits $0$ to $9$
Oct
4
revised Prove all multiples of $U$ contain all the digits $0$ to $9$
edited title
Oct
3
comment Is $x^{1-\frac{1}{n}}+ (1-x)^{1-\frac{1}{n}}$ always irrational?
@Slade You're right - this started out as a proof that there are no counterexamples for $n>2$ of that specific type, and then I forgot what I was trying to do. There may be counterexamples of a more general form.