User Carl Mummert

296 votes

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Can every proof by contradiction also be shown without contradiction?

answered Nov 24, 2012 at 18:08

131 votes

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Is there a known well ordering of the reals?

answered Oct 11, 2010 at 11:37

101 votes

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What's the difference between predicate and propositional logic?

answered Nov 9, 2010 at 12:10

95 votes

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Using proof by contradiction vs proof of the contrapositive

answered Mar 9, 2014 at 13:33

78 votes

In a family with two children, what are the chances, if one of the children is a girl, that both children are girls?

answered Dec 23, 2010 at 15:47

77 votes

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What is an Empty set?

answered Apr 28, 2015 at 10:38

75 votes

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What is the value of $1^i$?

answered Aug 30, 2010 at 22:04

72 votes

Do We Need the Axiom of Choice for Finite Sets?

answered Apr 17, 2012 at 11:31

55 votes

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Does mathematics require axioms?

answered Apr 21, 2013 at 18:08

55 votes

What is a proof?

answered May 21, 2013 at 12:05

54 votes

Why is establishing absolute consistency of ZFC impossible?

answered Apr 17, 2016 at 18:36

52 votes

Are "if" and "iff" interchangeable in definitions?

answered Nov 15, 2013 at 13:17

49 votes

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What's the difference between material implication and logical implication?

answered Oct 1, 2011 at 2:52

49 votes

What actually is a polynomial?

answered Mar 14, 2017 at 0:36

49 votes

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Examples of theorems that are true conceptually, but false computationally

answered Jul 4, 2018 at 12:11

49 votes

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$e^{e^{e^{79}}}$ and ultrafinitism

answered Dec 5, 2010 at 2:37

48 votes

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Is it possible to generate truly random numbers using a computer?

answered Dec 13, 2016 at 12:18

46 votes

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Preimage of generated $\sigma$-algebra

answered Oct 26, 2010 at 11:16

44 votes

Infinite sets don't exist!?

answered Apr 10, 2013 at 2:36

44 votes

How to avoid perceived circularity when defining a formal language?

answered Sep 25, 2012 at 11:57

43 votes

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Are the rationals minus a point homeomorphic to the rationals?

answered Dec 10, 2010 at 12:24

39 votes

What is the difference between a point and a vector?

answered Jan 21, 2014 at 1:32

39 votes

In what sense are math axioms true?

answered Apr 2, 2012 at 11:55

39 votes

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$\arcsin$ written as $\sin^{-1}(x)$

answered Apr 1, 2011 at 13:43

39 votes

What does $dx$ mean?

answered Dec 13, 2013 at 15:19

38 votes

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Why do we restrict the definition of Lebesgue Integrability?

answered Mar 18, 2011 at 11:21

37 votes

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(Why) is topology nonfirstorderizable?

answered Jun 21, 2011 at 12:01

37 votes

Why did mathematicians take Russell's paradox seriously?

answered Mar 2, 2011 at 3:20

37 votes

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Is it possible to formulate category theory without set theory?

answered Nov 9, 2015 at 14:14

37 votes

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Recursive vs. inductive definition

answered Nov 4, 2012 at 13:28

Stack Exchange Network

1,118 Answers

Can every proof by contradiction also be shown without contradiction?

Is there a known well ordering of the reals?

What's the difference between predicate and propositional logic?

Using proof by contradiction vs proof of the contrapositive

In a family with two children, what are the chances, if one of the children is a girl, that both children are girls?

What is an Empty set?

What is the value of $1^i$?

Do We Need the Axiom of Choice for Finite Sets?

Does mathematics require axioms?

What is a proof?

Why is establishing absolute consistency of ZFC impossible?

Are "if" and "iff" interchangeable in definitions?

What's the difference between material implication and logical implication?

What actually is a polynomial?

Examples of theorems that are true conceptually, but false computationally

$e^{e^{e^{79}}}$ and ultrafinitism

Is it possible to generate truly random numbers using a computer?

Preimage of generated $\sigma$-algebra

Infinite sets don't exist!?

How to avoid perceived circularity when defining a formal language?

Are the rationals minus a point homeomorphic to the rationals?

What is the difference between a point and a vector?

In what sense are math axioms true?

$\arcsin$ written as $\sin^{-1}(x)$

What does $dx$ mean?

Why do we restrict the definition of Lebesgue Integrability?

(Why) is topology nonfirstorderizable?

Why did mathematicians take Russell's paradox seriously?

Is it possible to formulate category theory without set theory?

Recursive vs. inductive definition