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Jul
23
comment A set of all rational numbers in $[0, 1]$?
And a set is dense in other (in topology), when its closure is the whole enclosing set. It is mentioned in wikipedia too.
Jul
23
comment A set of all rational numbers in $[0, 1]$?
$\bar{A}$ is the closure operation: adding all limiting points to a set in the topological sense. Some texts use $Cl(A)$ instead, like in wikipedia: en.wikipedia.org/wiki/Closure_(topology). See the link :)
Jul
23
suggested suggested edit on A set of all rational numbers in $[0, 1]$?
Jul
23
answered A set of all rational numbers in $[0, 1]$?
Jun
13
comment Is this question too easy or am I getting it wrong?
If I remember correctly (in Spivak's) $e^x$ is defined through its Taylor series and proved continuous that way.
Jun
12
comment Is this question too easy or am I getting it wrong?
Attention readers: this is the answer! The one flagged by the PO is a circular definition.
Jun
12
answered Mathematics textbooks with history and/or motivation?
Jun
6
answered What jobs in Mathematics are always in demand, and are deeply Mathematically specialised or greatly general?
Jun
2
comment Identification of a curious function
@Yuval, I saw something similar when reviewing election strategies (as in Politics) in an election where people vote for a list of candidates, there is a number of places to be elected $N$ (say a senate), and lists get as many places as percentage votes won: $places = floor(N P_l)$. The tricky part was that there is a remanent after allocating all lists, as one cannot allocate a fraction of a place, an allocation then was from greatest residual to lowest. So, what's the best strategy, split the party in many lists or nominate a single one? Plotting, we arrive at something similar.
May
29
revised Why is it that $\int_a^b \int_c^d f(x)g(y)\,dy\,dx=\int_a^b f(x)\,dx \int_c^d g(y)\,dy$?
added 29 characters in body
May
29
revised Why is it that $\int_a^b \int_c^d f(x)g(y)\,dy\,dx=\int_a^b f(x)\,dx \int_c^d g(y)\,dy$?
added 2 characters in body
May
29
revised Why is it that $\int_a^b \int_c^d f(x)g(y)\,dy\,dx=\int_a^b f(x)\,dx \int_c^d g(y)\,dy$?
added 2 characters in body
May
29
answered Why is it that $\int_a^b \int_c^d f(x)g(y)\,dy\,dx=\int_a^b f(x)\,dx \int_c^d g(y)\,dy$?
May
29
comment Logic and mathematical variables as objects
Also, the concept of valuation is from model theory. But it seems you want to "internalise" valuation for the variable type. So, sorry about the confusion; although you will need some sort of semantic for your logic anyway...
May
28
comment Logic and mathematical variables as objects
@Angelorf, I updated my pseudo-answer; good luck!
May
28
revised Logic and mathematical variables as objects
added 363 characters in body
May
28
awarded  Teacher
May
28
answered Logic and mathematical variables as objects
Apr
23
comment Digits of $n$ factorial
@Arthur, you are right is the most likely thing to happen. I bet looking at the Ring $Z_b$ where $b$ is the base, or even $Z_{b^L}$, being $L$ a fixed maximum length under consideration should settle the matter quickly. This also would explain, if this is the case, why the first digit (or any fixed length initial sequence) does not seem to be random.
Apr
23
asked Digits of $n$ factorial