chibro2
  • Member for 8 years, 7 months
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2 answers
6 votes
16k views
5 bookmarks
What's the expectation of square root of Chi-square variable?
1 answers
6 votes
453 views
1 bookmarks
Suppose some theory T has countably many axioms, how many models of $T$ are there of cardinality $\aleph_1$,$\aleph_2$,$\aleph_{\omega_1}$?
1 answers
6 votes
2k views
3 bookmarks
Using first order sentences, axiomize the $\mathcal{L}$-theory of an equivalence relation with infinitely many infinite classes.
3 answers
5 votes
2k views
How would you define the set of even numbers in $\mathbb{Z}$ using a first order sentence?
2 answers
4 votes
1k views
3 bookmarks
What is the expected value of $\min\{|X|,|Y|\}/\max\{|X|,|Y|\}$ assuming $X$ and $Y$ are independent?
2 answers
4 votes
2k views
4 bookmarks
What are some applications of model theory?
4 answers
4 votes
765 views
Show the probability that the sum of these numbers is odd is 1/2
5 answers
3 votes
499 views
1 bookmarks
Check my proof of "overspill" in non-standard models of Peano arithmetic.
1 answers
3 votes
8k views
2 bookmarks
How do you find angular velocity given a pair of 3x3 rotation matrices?
1 answers
3 votes
181 views
2 bookmarks
Prove this proposition concerning a theory with ∀∃-axiomatization part II.
0 answers
3 votes
305 views
Proving amalgamation property in model theory
1 answers
3 votes
596 views
2 bookmarks
Prove elementary amalgamation theorem in model theory.
2 answers
3 votes
2k views
1 bookmarks
The limit of an expected value vs expected value of a limit in this betting game
2 answers
2 votes
488 views
1 bookmarks
If T is forall/exists-axiomatizable and M,N satisfies T, then there is exists/forall sentence $\psi$ so that If M sat $\psi$, then N sat $\psi$
2 answers
2 votes
297 views
probability that I toss two coins independently, and get two heads or two tails, assuming I discard all HT and TH outcomes.
1 answers
2 votes
228 views
1 bookmarks
Probability of a path on a graph under a random walk
1 answers
2 votes
283 views
Show For any language L two L-structures M and N are elementarily equivalent iff they are elementarily equivalent for every finite sublanguage.
1 answers
2 votes
274 views
1 bookmarks
Complete $n$-types for the theories of $( \mathbb Z , s )$ and $( \mathbb Z , s , < )$
2 answers
2 votes
103 views
1 bookmarks
Please unpack this notation from book Model Theory by Marker
2 answers
2 votes
612 views
2 bookmarks
A first order sentence such that the finite spectrum of that sentence is the following subsets of $\mathbb{N}^+$.
2 answers
2 votes
208 views
1 bookmarks
Examine my argument that $\mathbb{Z} \oplus \mathbb{Z} \not\equiv \mathbb{Z}$
1 answers
2 votes
87 views
Walk me through the proof that the class of graphs is elementary.
1 answers
2 votes
29 views
1 bookmarks
Determine the density of this problem
1 answers
2 votes
880 views
Prove or disprove convergence in distribution of a poisson variable.
1 answers
2 votes
54 views
Find the unit vector so that this condition is true.
1 answers
2 votes
1k views
1 bookmarks
Expected value of a Poisson variable conditioned on sum
2 answers
2 votes
37 views
Solve for a variable in the power when the base are two different values
0 answers
1 votes
409 views
Python integer linear programming program does not behave as expected
2 answers
1 votes
96 views
Non isolated types of $\mathcal M$ cannot be isolated in $\mathcal N \succ \mathcal M$?
1 answers
1 votes
1k views
Show that if $P = NP$, then deciding whether a boolean formula is minimal is in $P$.