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9h
asked Are all 7-dimensional cross products isomorphic?
1d
comment Differentiating the exponent power series
"uniformly convergent everywhere" $\: \mapsto \:$ "locally uniformly convergent everywhere" $\hspace{1.48 in}$
2d
revised When is a graph balanced bipartite?
fixed grammar
2d
comment Minimum distance between closed sets.
"are disjoint" $\: \mapsto \:$ "are non-empty and disjoint" $\;\;\;\;$
Jul
2
comment Non-standard model of $Th(\mathbb{R})$ with the same cardinality of $\mathbb{R}$
One can just add the axioms $\;\;\; 1\hspace{-0.05 in}+\hspace{-0.05 in}1+...\hspace{-0.05 in}+1\hspace{-0.05 in}+\hspace{-0.05 in}1 \: < \: c \;\;\;$ instead. $\;\;\;\;\;\;\;\;$
Jul
2
revised Extended version of the theory of reals and its decidability
fixed mis-quote
Jul
1
revised How can we check that for a given norm, we can found an inner product?
improved grammar
Jul
1
revised What are the products of real solutions of this equation?
general copy-editing
Jun
30
answered Summation of “products”
Jun
30
answered Example of a ring with infinitely many zero divisors and finitely many invertible elements
Jun
30
revised Open (closed) sets of a locally compact space.
fixed punctuation
Jun
30
comment Is there something between summation and integration?
@Solomonoff'sSecret : $\:$ See my previous comment. $\;\;\;\;$
Jun
30
comment Is there something between summation and integration?
@RoryDaulton : $\:$ The counting measure on $\mathbb{Q}$ is "a uniform, countably-additive measure" on $\mathbb{Q}$. $\hspace{.63 in}$
Jun
29
comment Why is $f(x,y)$ said to be discontinuous at $(0,0)$?
You missed the curve $\: y = x^2 \;$. $\;\;\;\;$
Jun
29
comment Open (closed) sets of a locally compact space.
There is no question in the opening post. $\;$
Jun
28
comment Proof of the derivative of ln(x)
For this method, you also need to know that $\: \ln \:$ is differentiable. $\;\;\;\;$
Jun
28
comment Existence of an infinite subset
It's not something that should be obvious, but it also doesn't need a pathological set. $\:$ To start, try finding "an infinite subset S of" $\mathbb{R}^2$ "such that any" two "vectors in S are linearly independent". $\;\;\;\;$
Jun
28
answered Why an open set in $R^n$ might not be written as countable union of disjoint open intervals?
Jun
28
asked What logical resources does one need to distinguish $\mathbb{R}\hspace{-0.05 in}-\hspace{-0.04 in}\mathbb{Q}$ from $\mathbb{Q}$?
Jun
26
answered Extended version of the theory of reals and its decidability