CptSupermrkt's user avatar
CptSupermrkt's user avatar
CptSupermrkt's user avatar
CptSupermrkt
  • Member for 10 years, 8 months
  • Last seen more than 3 years ago
  • Tokyo, Japan
20 votes
3 answers
74k views

Prove that at a party with at least two people, there are two people who know the same number of people.

15 votes
2 answers
3k views

Where, specifically, did Principia Mathematica fail?

15 votes
7 answers
6k views

Prove that the additive inverse of an odd integer is an odd integer

6 votes
4 answers
6k views

Prove that $\lfloor\lfloor x/2 \rfloor / 2 \rfloor = \lfloor x/4 \rfloor$

6 votes
2 answers
23k views

Algebraic proof of De Morgan's law with three sets

5 votes
3 answers
983 views

How can one simplify $¬(¬∃x, P(x)) $ and $\neg(\neg\forall x,P(x))$?

5 votes
5 answers
176 views

Help understanding $x=y\Rightarrow(x=z\Rightarrow y=z)$

4 votes
1 answer
1k views

"Rules of inference" when the last premise is a conditional?

3 votes
5 answers
4k views

Are (some) axioms "unprovable truths" of Godel's Incompleteness Theorem?

2 votes
2 answers
108 views

What is the absolute minimum that must be accepted/defined in order to prove 1+1=2?

2 votes
2 answers
355 views

How can I definitively determine whether a universal/existential statement is true or false?

2 votes
4 answers
9k views

Pigeonhole principle: show that a class of nine has at least five male or five female students.

1 vote
2 answers
16k views

Basic discrete math question regarding translation of logic ↔ English

1 vote
2 answers
2k views

Can anyone provide me a step-by-step proof for proving a function IS onto/surjective?

1 vote
2 answers
2k views

What does it mean to "compute" a generic formula without values?