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ngc1300
  • Member for 6 years, 10 months
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5 votes
4 answers
743 views

The relationship between a statement and a theorem

3 votes
1 answer
148 views

Definition of a function and its graph

3 votes
2 answers
90 views

Theory of a first order structure

3 votes
1 answer
203 views

Product associativity in category theory

2 votes
1 answer
772 views

Electric potential due to dipole layer

2 votes
1 answer
518 views

⊢∃𝑥(𝜙⟹∀𝑥𝜙) using Hilbert-style proof [duplicate]

2 votes
1 answer
912 views

Derivation of Snells Law using boundary conditions

2 votes
6 answers
3k views

Integer $a$ that divides $bc$ but does not divide $b$ or $c$

2 votes
4 answers
2k views

Show that $n^{13} - n$ is divisible by 2, 3, 5, 7, 13 [duplicate]

2 votes
1 answer
73 views

Does (∀x(r → p)) ∧ (∀x(p → q)) imply ∀x(r → q)?

1 vote
2 answers
71 views

Let $A⊆B⊆C$ and $X<Y$ denote $X$ is an elementary substructure of $Y.$ Does $A<B$ and $A<C$ imply $B<C$?

1 vote
2 answers
47 views

What are the eigenvalues of T?

1 vote
2 answers
991 views

General solution to homogeneous 1D wave equation

1 vote
2 answers
418 views

Proofs and Metalanguage

1 vote
0 answers
36 views

Axiom of Extensionality and defining the notion of set equality [duplicate]

1 vote
1 answer
186 views

$a \in A$ is equivalent to $ \{ a \} \subset A $

1 vote
0 answers
209 views

Why do we care about PA proving itself consistent?

1 vote
0 answers
77 views

Elementarily equivalent models of arithmetic that are not isomorphic.

1 vote
0 answers
51 views

Existence conditions for integral transforms

1 vote
4 answers
386 views

Proof that $\nabla \times E = 0$ using Stokes's theorem

1 vote
1 answer
50 views

Deriving Fresnel diffraction from Huygen's principle

1 vote
0 answers
55 views

Huygens' principle for diffraction through an apeture

1 vote
1 answer
459 views

How many formulas can you make (up to equivalence) with $n$ propositions?

0 votes
0 answers
33 views

Translational invariance of sources/materials implies translational field invariance

0 votes
0 answers
43 views

Change of basis for reflection across a line

0 votes
1 answer
122 views

Completeness of real closed fields within ZFC

0 votes
1 answer
51 views

Quantifiers and usage of the infinum

0 votes
0 answers
44 views

Prove tail series tends to $0$ using contradiction

0 votes
0 answers
157 views

Reverse deduction theorem for predicate logic

0 votes
2 answers
413 views

Formula term-substitution in first order logic