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Peter LeFanu Lumsdaine's user avatar
Peter LeFanu Lumsdaine's user avatar
Peter LeFanu Lumsdaine's user avatar
Peter LeFanu Lumsdaine
  • Member for 13 years, 8 months
  • Last seen this week
288 votes
Accepted

How do you explain to a 5th grader why division by zero is meaningless?

42 votes
Accepted

An interesting problem with "decomposing" natural numbers.

26 votes

Given an infinite number of monkeys and an infinite amount of time, would one of them write Hamlet?

24 votes
Accepted

A polynomial is completely determined by any part of it

21 votes
Accepted

In category theory why is a right adjoint not a left adjoint?

21 votes
Accepted

Which step in this process allows me to erroneously conclude that $i = 1$

20 votes

Direct sums and direct products

19 votes
Accepted

Is every monoid isomorphic to its opposite

17 votes

Is this of any real importance to the mathematical scientific community?

17 votes

How would you explain to a 9th grader the negative exponent rule?

17 votes

Where is the mistake in the argument in favor of the (erroneous) claim "every Dedekind cut is a rational cut"?

16 votes
Accepted

Prove that $x^4-y^4=1996$ has no integer root.

16 votes

A Question about Doctoral Theses in Mathematics

15 votes

$\sqrt 2$ is even?

13 votes

Finite covering is compact Hausdorff iff base space is

13 votes

Given that it appears impossible to make the set out of linear combinations of its elements, why is it still dependent?

13 votes

Can somebody explain to me Cantor's diagonalization argument?

13 votes

Understanding Universal Quantifiers (Order Matters)

12 votes
Accepted

Why not $\{\{a\},\{b, \emptyset \}\}$ as the ordered pairs?

12 votes

In homotopy type theory, what are the intermediate values along a path?

12 votes

Why is two to the power of zero equal to binary one?

11 votes

Why $\mathbb{R}[X]/(X^2+1)\cong\mathbb{C}$?

11 votes

Why is the Principle of Explosion considered constructive?

11 votes

In how many ways the letters of the word "LOCKDOWN" can be arranged such that N is always between O's?

11 votes

Does a homeomorphism preserve the open sets?

10 votes
Accepted

Is "William only eats icecream when the sun is shining" a biimplication?

10 votes

Definition of presheaf, given in Basic Algebraic geometry 2 Shafarevich

10 votes

Examples of non-continuous, non-piecewise-constant, idempotent map?

10 votes

What's so special with small categories?

10 votes

Partitioning an infinite set