User Dan Öz

0 votes

0 answers

45 views

An injection from $\mathcal{P} (\mathbb{Z^{+})}$ to $\mathcal{P} (\mathbb{ N \times N)}$

asked Dec 14, 2022 at 17:23

1 vote

2 answers

103 views

If there is an surjection $f : \Bbb{Z}^+ \to a$, then there is an injection $f : a \to \Bbb{Z}^+$ [duplicate]

asked Dec 7, 2022 at 18:48

0 votes

1 answer

23 views

Confusion about the import of the standard error

asked Dec 7, 2022 at 11:12

5 votes

2 answers

121 views

Confusion on the definition of the inverse function

asked Dec 6, 2022 at 18:52

0 votes

1 answer

27 views

For any sentence $\phi$ of first-order logic, the only sentence which is an initial segment of $\phi$ is $\phi$ itself.

asked Nov 17, 2022 at 23:02

1 vote

1 answer

54 views

Simple proof of $\phi \rightarrow \neg \neg \phi$

asked Nov 17, 2022 at 12:44

0 votes

0 answers

33 views

Proof of $\forall y(Sx + y = S(x + y))$ in Peano Arithmetic.

asked Nov 17, 2022 at 11:24

0 votes

1 answer

46 views

Explicit Substitution in Peano Arithmetic proofs.

asked Nov 16, 2022 at 11:47

2 votes

2 answers

395 views

Proof in Peano Arithmetic

asked Nov 8, 2022 at 15:46

0 votes

0 answers

38 views

I don't trust my proof of $ \neg ( \phi \rightarrow \neg \psi) \vdash \phi$

asked Nov 7, 2022 at 14:38

0 votes

1 answer

62 views

Is my axiomatic proof of $\phi \vdash \neg \neg \phi$ correct?

asked Nov 4, 2022 at 11:53

3 votes

1 answer

110 views

Axiomatic derivation of conditional from biconditional

asked Nov 2, 2022 at 17:38

0 votes

0 answers

24 views

For any sentence $A$, the only sentence which is an initial segment of $A$ is $A$ itself

asked Nov 1, 2022 at 18:27

0 votes

1 answer

42 views

Probability that a sample of sweets is rejected

asked Oct 31, 2022 at 19:18

0 votes

1 answer

83 views

How to enforce symmetry in a combination problem?

asked Oct 31, 2022 at 10:45

0 votes

0 answers

37 views

Assessing my proof about first-order Logic

asked Oct 30, 2022 at 19:22

0 votes

0 answers

49 views

I am defeated by the following propositional logic axiomatic proof:

asked Oct 26, 2022 at 18:42

1 vote

1 answer

24 views

How to think about changes to the median

asked Oct 24, 2022 at 17:13

0 votes

0 answers

31 views

How to determine whether a data set is symmetric or approximately symmetric

asked Oct 17, 2022 at 21:37

2 votes

3 answers

408 views

How to formulate an induction principle for the set of all integers?

asked Oct 6, 2022 at 15:43

0 votes

0 answers

50 views

Let R be a relation and A and B sets. Suppose A is a subset of B. If A is not empty, and R is transitive on A, must it also be transitive on B?

asked Sep 7, 2022 at 18:26

11 votes

4 answers

778 views

What is the relation between the high school definition of a vector and the abstract algebra definition?

asked Jul 30, 2022 at 15:48

0 votes

0 answers

47 views

Why are all fields vector spaces over themselves?

asked Jul 29, 2022 at 10:27

5 votes

1 answer

449 views

What is the difference, geometrically, between row vectors and column vectors?

asked Jul 27, 2022 at 16:19

0 votes

3 answers

305 views

Why is the conditional probability formula not the intersection of A and B over A, rather than the intersection over P(A)?

asked Jun 23, 2022 at 15:27

0 votes

0 answers

24 views

How do I show a non-geometric and non-arithmetic series converges? [duplicate]

asked Jun 16, 2022 at 10:28

0 votes

0 answers

65 views

Why can we treat the numerator as a constant in partial fractions?

asked May 26, 2022 at 10:29

2 votes

2 answers

145 views

What is the intuition behind the probability intersection formula?

asked Apr 19, 2022 at 9:20

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28 Questions

An injection from $\mathcal{P} (\mathbb{Z^{+})}$ to $\mathcal{P} (\mathbb{ N \times N)}$

If there is an surjection $f : \Bbb{Z}^+ \to a$, then there is an injection $f : a \to \Bbb{Z}^+$ [duplicate]

Confusion about the import of the standard error

Confusion on the definition of the inverse function

For any sentence $\phi$ of first-order logic, the only sentence which is an initial segment of $\phi$ is $\phi$ itself.

Simple proof of $\phi \rightarrow \neg \neg \phi$

Proof of $\forall y(Sx + y = S(x + y))$ in Peano Arithmetic.

Explicit Substitution in Peano Arithmetic proofs.

Proof in Peano Arithmetic

I don't trust my proof of $ \neg ( \phi \rightarrow \neg \psi) \vdash \phi$

Is my axiomatic proof of $\phi \vdash \neg \neg \phi$ correct?

Axiomatic derivation of conditional from biconditional

For any sentence $A$, the only sentence which is an initial segment of $A$ is $A$ itself

Probability that a sample of sweets is rejected

How to enforce symmetry in a combination problem?

Assessing my proof about first-order Logic

I am defeated by the following propositional logic axiomatic proof:

How to think about changes to the median

How to determine whether a data set is symmetric or approximately symmetric

How to formulate an induction principle for the set of all integers?

Let R be a relation and A and B sets. Suppose A is a subset of B. If A is not empty, and R is transitive on A, must it also be transitive on B?

What is the relation between the high school definition of a vector and the abstract algebra definition?

Why are all fields vector spaces over themselves?

What is the difference, geometrically, between row vectors and column vectors?

Why is the conditional probability formula not the intersection of A and B over A, rather than the intersection over P(A)?

How do I show a non-geometric and non-arithmetic series converges? [duplicate]

Why can we treat the numerator as a constant in partial fractions?

What is the intuition behind the probability intersection formula?