10,340 reputation
41560
bio website tetori.blog.me
location South Korea
age 19
visits member for 2 years, 1 month
seen 13 mins ago

I am not good at English, so any correction of grammatical error would be welcomed.


24m
comment Non analytic ideals on $\omega$
@GregSmiley It is consistent with ZF that every subset of reals is Borel, so I think that there is no example given from ZF only.
6h
reviewed Reopen An example of a great explanation or freely accessible article on a math concept
6h
revised Calculate cardinality of 8-digit strings composed of zeros and ones
edited tags
6h
comment Non analytic ideals on $\omega$
Sorry, but I cannot certain the meaning of 'analytic ideals'. What is the meaning of that? My thought is: since every subset of $\omega$ would be considered as a point in the Cantor set, we can construct the corresponding subset of the Cantor set with given ideal therefore we can talk about analyticity of ideal. Am I correct?
2d
awarded  Announcer
Jan
22
reviewed Reopen What can we say about the stability of stable points?
Jan
22
comment Does $A\times A\cong B\times B$ imply $A\cong B$?
@TonyK Yes. If every cardinals are comparable, then every set can embed into some ordinal. To be more exact, Hartogs number of the set has larger cardinality than the set.
Jan
22
revised Does $A\times A\cong B\times B$ imply $A\cong B$?
added 425 characters in body
Jan
22
answered Does $A\times A\cong B\times B$ imply $A\cong B$?
Jan
21
reviewed Leave Closed Probablity in dice game
Jan
21
reviewed Leave Closed Power method convergence explanation.
Jan
21
reviewed Leave Closed For a non-unit element $x$ in a unital ring, does non-zero $a$ or $b$ ALWAYS exist s.t. $ax=xb=0$?
Jan
20
reviewed Leave Closed plane throw two points and paralell to another plane
Jan
20
reviewed Reopen Why do transcendental numbers exist?
Jan
20
reviewed Reopen Deduce $\lvert ab\rvert = \lvert ba\rvert$ for all $a,b\in G$ where $G$ is a group.
Jan
20
reviewed Approve Equation $e^{\frac{1}{x}} - x =0$
Jan
20
reviewed No Action Needed Numbers $n$ such that the digit sum of $n^2$ is a square
Jan
20
reviewed No Action Needed Help me get started on calculating CDFs/PDFs
Jan
20
revised Math surface question which I don't know how to solve
edited tags
Jan
19
reviewed No Action Needed What's the relationship between the rank and eigenvalues of symmetric positive semidefinite matrix (real domain)?