211 reputation
16
bio website problemania.org
location Problemania
age
visits member for 1 year, 8 months
seen Apr 7 at 6:28

A moderator at Wiki site http://problemania.org where a group of enthusiasts enjoying sharing the fun solving mathematics, physics, and computing problems. We primarily work on problems found in college/grad school text books.

Web page: http://problemania.org

Twitter: http://twitter.com/problemania

Github: https://github.com/Problemaniac


Apr
6
comment “important” math concepts to pass on to next generation of creatures at some cataclysm
If you add this explanation in the original answer, it probably would not get down votes.
Apr
6
revised “important” math concepts to pass on to next generation of creatures at some cataclysm
added 23 characters in body
Apr
6
revised “important” math concepts to pass on to next generation of creatures at some cataclysm
added 23 characters in body
Apr
6
revised “important” math concepts to pass on to next generation of creatures at some cataclysm
added 179 characters in body; edited tags
Apr
6
awarded  Yearling
Apr
6
awarded  Critic
Apr
6
asked “important” math concepts to pass on to next generation of creatures at some cataclysm
Mar
22
accepted Why Euler-Lagrange equation does not depend on the second derivative of the function?
Mar
22
comment How to prove a Set category with at least one element is a separator?
@BrunoStonek, thanks for reminding me of that. That's exactly right. A separator is for a category, and it separates any pair of two different morphisms. I'm trying to I've finally written down the reasoning more formally as a note.
Mar
17
accepted How to inverse this logic definition of separator of Set category?
Mar
17
comment How to inverse this logic definition of separator of Set category?
Is $\bar{s}_3$ the correct answer?
Mar
17
revised How to inverse this logic definition of separator of Set category?
added 127 characters in body
Mar
17
comment How to inverse this logic definition of separator of Set category?
Now, I'm confused. You said above "it's the second $\Rightarrow$ in $\bar{s}_2$". But $\bar{s}_2$ only has ONE $\Rightarrow$.
Mar
16
awarded  Commentator
Mar
16
comment How to inverse this logic definition of separator of Set category?
The second "$\Rightarrow$" is after $X$.
Mar
16
revised How to inverse this logic definition of separator of Set category?
added 8 characters in body
Mar
16
revised How to inverse this logic definition of separator of Set category?
added 124 characters in body
Mar
16
comment How to inverse this logic definition of separator of Set category?
There're two $\Rightarrow$'s in it, which one should be replaced by $\land$?
Mar
16
revised How to inverse this logic definition of separator of Set category?
added 15 characters in body
Mar
16
asked How to inverse this logic definition of separator of Set category?