user avatar
user avatar
user avatar
Ivan Hieno
  • Member for 5 years, 11 months
  • Last seen more than a week ago
  • Санкт-Петербург
6 votes
1 answer
342 views

An infinite list of irrational numbers from one irrational number.

6 votes
2 answers
657 views

I've been told that the use of ellipsis in "$S = x_1 + x_2 + x_3 + x_4 + \dots$" is ambiguous and meaningless. Is it?

3 votes
2 answers
310 views

Cardinality of the irrational numbers vs the rationals

3 votes
5 answers
3k views

Is a surjection from the natural numbers enough to show that a set is countable?

2 votes
1 answer
203 views

How many segments are there in the Cantor set?

2 votes
1 answer
170 views

Can we define the Cantor Set in this way?

2 votes
3 answers
187 views

Equality of irrational numbers and the need for a proof

2 votes
1 answer
98 views

What is this curve called?

2 votes
2 answers
202 views

How can we prove that there is a finite set for every infinite set, in an infinite list of infinite sets.

2 votes
2 answers
223 views

Does an element of a set, that can't be in a list, make that set uncountable?

1 vote
1 answer
70 views

Defining an infinite list of irrational numbers

1 vote
3 answers
1k views

Can a set be uncountable if it is the union of an uncountable quantity of finite objects?

1 vote
2 answers
185 views

Is this a paradox in the Cantor set?

1 vote
2 answers
493 views

Is an infinite set of disjoint subsets of the natural numbers with an infinite number of members each, countable or uncountable.

1 vote
2 answers
114 views

How do you read this in words?

0 votes
1 answer
114 views

Is this a valid set?

0 votes
1 answer
80 views

Is this a valid representation of pi?

0 votes
1 answer
2k views

Is the empty set always a member of the universal set?

0 votes
2 answers
1k views

Can we prove that the set of irrational numbers is uncountable without Cantor? [duplicate]

0 votes
2 answers
49 views

Are these formulas proper notation?

0 votes
1 answer
37 views

Do I need parenthesis in this equation or is the hierarchy of the symbols enough?

0 votes
2 answers
55 views

When can we say that something is equal to, rather than something approaches a limit?

-1 votes
1 answer
114 views

Will Cantor's diagonalization always produce a set that is not on the list?

-2 votes
3 answers
90 views

Does the diagonal proof lack rigor?

-2 votes
2 answers
53 views

Infinite regression and the limits of the density of rational numbers vs irrational numbers.

-2 votes
2 answers
155 views

Uncountable Sets and an Infinite Real Number Game

-3 votes
3 answers
698 views

Can we find an injection from the set of irrational numbers to a list of rational numbers that terminate