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Marc van Leeuwen

Poitiers, France

www-math.univ-poitiers.fr/~maavl

Age: 53

professor of mathematics at the Université de Poitiers (France)

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Top Questions
Top Answers
25
$m!n! < (m+n)!$ Proof?
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24
Which symbol should be used for an empty set?
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22
How to learn from proofs?
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21
Why isn't $\lim_{x\to\infty}(1+\frac{1}{x})^{x}= 1$?
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18
Can anyone explain why $a^{b^c} = a^{(b^c)} \neq (a^b)^c = a^{(bc)}$
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17
Does “This is a lie” prove the insufficiency of binary logic?
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16
Can $\mathbb RP^2$ cover $\mathbb S^2$?
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15
$GL_n(\mathbb{R})$ is cyclic?
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13
Why doesn't induction extend to infinity? (re: Fourier series)
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13
Find a $4\times 4$ matrix $A$ where $A\neq I$ and $A^2 \neq I$, but $A^3 = I$.
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12
Is it better to play 1 dollar on 10 lottery draws or 10 dollars on one lottery draw?
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11
GCD of rationals
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11
Find an integer $n$ such that $\mathbb{Z}[\frac{1}{20},\frac{1}{32}]=\mathbb{Z}[\frac{1}{n}]$.
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11
What is $x^y$? How to understand it?
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11
When can I say that $\cup H_i$ is a group?
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10
Do absolute values of differentiable functions with roots always exhibit cusps?
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10
Is it possible to write a number in a base of less than 1?
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10
Is there a topological notion of the derivative?
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10
What is the norm of a complex number?
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10
Do we really need polynomials (In contrast to polynomial functions)?
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9
How many trees in a forest?
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9
Is every positive nonprime number at equal distance between two prime numbers?
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9
How to make something that will cap on 20?
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9
The first column of the $n$th power for a triangular matrix
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9
Fundamental group of $SO(3)$
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9
Does every prime ideal in a ring arise as kernel of a homomorphism into $\mathbb{Z}$?
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9
The notation $\prod_{g\in G} g$ for a finite group not well-defined.
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9
Intervals that are free of primes
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8
Example of a finitely generated module with submodules that are not finitely generated
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8
square that can be written as mean of as many pairs of squares as possible
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