User Popopo - Mathematics Stack Exchange

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visits	member for	11 months
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	609 reputation	bio	website		visits	member for	11 months
226 badges		location	Pop Star, MathCraft		seen	16 hours ago

1

4

votes

1

answer

76

views

Which logic is stronger? SOL or $\frak{L}_{\infty,\infty}$?

logic model-theory

apr 27 at 15:19 Peter Smith 11.6k

1

8

votes

2

answers

98

views

Can we conclude $\prod_{\kappa \in Crd, \kappa=1}^{\kappa<\aleph_\alpha}\kappa=2^{\aleph_\alpha}$ in ZFC?

elementary-set-theory cardinals

apr 16 at 13:31 Andres Caicedo 24.4k

0

votes

0

answers

33

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Can we conclude that $|\prod_{\xi \in Ord, \xi=1}^{\xi<\alpha}\xi|=2^{|\alpha|}$ for all infinite ordinal $\alpha$ in $\mathsf{ZFC}$?

elementary-set-theory cardinals ordinals

apr 16 at 11:59 Popopo 609

2

votes

2

answers

61

views

What's the remainder of a natual number divided by lcm(m,n)?

elementary-number-theory

apr 6 at 8:17 Popopo 609

2

votes

1

answer

48

views

How to deal with infinite continued fractions in formal language?

logic continued-fractions

apr 6 at 0:21 Henning Makholm 53.6k

6

votes

4

answers

144

views

Are there rules in the useage of prepositions in Math?

soft-question terminology article-writing

mar 30 at 18:09 amWhy 55.3k

4

votes

0

answers

98

views

What is the correspondence between the semantic compactness of logics and the compactness of Stone spaces?

logic model-theory

mar 27 at 19:33 Popopo 609

1

2

votes

2

answers

47

views

How to extend definition of n-tuple to the case $n=0$?

elementary-set-theory definition

mar 22 at 16:42 Arthur Fischer♦ 21.4k

5

votes

2

answers

102

views

Can proper classes also have cardinality?

set-theory cardinals

mar 22 at 8:01 Popopo 609

3

votes

2

answers

57

views

On models of ZFC, does there exist a bijection between Von Neumann universe and the ordinal class?

set-theory

mar 21 at 15:45 Brian M. Scott 155k

2

votes

1

answer

71

views

Is $\kappa^\lambda=2^\lambda$($2 \le \kappa<\lambda$,$\lambda$ infinite) valid in set models of ZF?

elementary-set-theory cardinals axiom-of-choice

mar 21 at 10:10 P.. 8,935

1

3

votes

2

answers

203

views

Proving that for infinite $\kappa$, $|[\kappa]^\lambda|=\kappa^\lambda$

set-theory cardinals

mar 14 at 12:24 Popopo 609

2

11

votes

2

answers

268

views

Hyperreal measure?

measure-theory elementary-set-theory nonstandard-analysis

mar 1 at 5:26 Popopo 609

1

2

votes

1

answer

50

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Is every homomorphism from $\langle(0,+\infty),\,\cdot\,,{}^{-1}\rangle$ into $\langle\{-1,1\},\,\cdot\,,{}^{-1}\rangle$ a constant valued function?

group-theory

jan 26 at 7:42 Zev Chonoles 54.2k

1

vote

4

answers

136

views

How to solve real-time games?

algorithms game-theory

jan 22 at 7:56 Michael Greinecker♦ 12.5k

4

votes

1

answer

270

views

Does Black have a winning strategy in Gomoku(freestyle)?

computational-complexity game-theory

jan 20 at 9:53 joriki 92.8k

1

3

votes

1

answer

244

views

Which side has winning strategy in Go?

game-theory open-problem

dec 27 at 19:22 Ed Pegg 2,111

0

votes

1

answer

102

views

Is one structure elementary equivalent to its elementary extension?

logic model-theory

dec 9 at 15:23 tomasz 7,190

1

vote

1

answer

59

views

Does elementary embedding exist between two elementary equivalent structures?

logic model-theory

dec 8 at 14:50 Zhen Lin 21.1k

1

vote

2

answers

79

views

Is there any Dedekind-infinite set can be split to two smaller Dedekind-infinite sets?

elementary-set-theory cardinals axiom-of-choice infinity

dec 2 at 12:47 Asaf Karagila 91.8k

1

vote

1

answer

44

views

$A+\alpha\sim A$ when $\omega\le\alpha<h(A)$

elementary-set-theory cardinals axiom-of-choice infinity

dec 2 at 11:22 Asaf Karagila 91.8k

4

votes

1

answer

100

views

Is this theory $\kappa$-categorical when $\kappa$ is infinite and not $\le \aleph_0$?

logic cardinals axiom-of-choice model-theory

dec 1 at 15:19 Asaf Karagila 91.8k

1

vote

1

answer

48

views

In class universe, on what basis can a conclusion that every element of a set is set be made?

elementary-set-theory axioms

nov 30 at 9:57 Asaf Karagila 91.8k

1

vote

1

answer

130

views

Is $\mathbb N$ definable in $\mathbb C$?

abstract-algebra logic model-theory

nov 29 at 12:27 Asaf Karagila 91.8k

1

4

votes

1

answer

82

views

Is $\aleph_0$ the minimum infinite cardinal number in $ZF$?

elementary-set-theory cardinals axiom-of-choice infinity

nov 29 at 10:55 Asaf Karagila 91.8k

0

votes

2

answers

38

views

Can a set(in ZFC) be well-ordered with any order type equipotent to it?

elementary-set-theory cardinals

nov 28 at 17:50 Asaf Karagila 91.8k

2

votes

2

answers

170

views

Is the negation of Gödel's completeness theorem consistent with $ZF$ without AC?

logic axiom-of-choice model-theory compactness

nov 27 at 19:13 Asaf Karagila 91.8k

1

7

votes

4

answers

372

views

What is straight line?

geometry metric-spaces definition philosophy

nov 26 at 6:14 Yury 3,368

0

votes

1

answer

57

views

How to compatilize convergence of functions as points and pointwise convergence of functions?

general-topology convergence

nov 19 at 14:13 Community♦ 1

1

vote

0

answers

118

views

Should every line be infinite in both two directions?

geometry metric-spaces

nov 18 at 15:27 Popopo 609

Popopo

58 Questions