bio | website | beroal.livejournal.com |
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location | ||
age | ||
visits | member for | 3 years, 9 months |
seen | Oct 9 '12 at 21:58 | |
stats | profile views | 120 |
Feb 3 |
awarded | Yearling |
Aug 8 |
awarded | Popular Question |
Jun 21 |
awarded | Popular Question |
Jul 21 |
comment |
Why is it so difficult to write complete (computer verifiable) proofs?
“These linear scripts are unreadable unless replayed step-by-step in the proof assistant.” +1. Elementary tactics killed readability in Coq. Not to mention that you must learn dozens (hundreds?) little tactics. Lambda-calculus is shorter. However, advanced tactics, like “ring”, are useful. |
Oct 17 |
revised |
a limit of $\operatorname{id}$
clarification |
Oct 17 |
comment |
a limit of $\operatorname{id}$
@Charles Rezk: You say that if $C$ has an initial object $0$, then $0$ is a limit of $\operatorname{id}(C)$? I could not prove this, can you hint me? |
Oct 17 |
comment |
a limit of $\operatorname{id}$
@S. Carnahan: Yes, you are right. Usually I ignore foundations and call everything a “set.” $C$ is the category of algebras, so it is usually infinite. The second paragraph gives additional info (perhaps it will be relevant) and motivation. I do not like questions without motivation. |
Oct 15 |
asked | a limit of $\operatorname{id}$ |
Sep 16 |
comment |
Do Arbib and Manes describe just concrete categories?
@Qiaochu Yuan: Thanks, I did not know that. I have removed “ct.”. |
Sep 16 |
revised |
Do Arbib and Manes describe just concrete categories?
“ct.” has been removed |
Sep 13 |
asked | Do Arbib and Manes describe just concrete categories? |
Aug 28 |
comment |
What is the theory of polynomials?
@Todd Trimble: BTW, Emil's answer would be great if I could understand it. :) |
Aug 28 |
comment |
What is the theory of polynomials?
@Todd Trimble: Not so slightly. Emil does not mention any adjunction, and I do not mention atomic=positive diagrams and associative algebras. I posted my answer because I could not follow Emil's answer because of a couple of unfamiliar terms. (Never heard of atomic=positive diagrams before. Now I see they are probably related to $\eta(R)$, though do not see how until I find the precise definition.) And I gave the reference. It is always good to know your predecessors and not to reinvent the wheel. :) |
Aug 28 |
revised |
What is the theory of polynomials?
added 10 characters in body |
Aug 27 |
awarded | Teacher |
Aug 27 |
answered | What is the theory of polynomials? |
Jul 16 |
comment |
a “self-dual” adjunction
@Finn Lawler: Thanks, that is exactly what I was looking for. The power-object functor is a particular case of contravariant exponential functors. Contravariant exponential functors lead to the continuation monad. I will probably stick to MacLane's term. |
Jul 16 |
comment |
a “self-dual” adjunction
@Finn Lawler: $I$ is a morphism between categories, i.e. a functor. |
Jul 14 |
asked | a “self-dual” adjunction |
May 24 |
comment |
Writing “Semi-Formal” Proofs
“He seemed skeptical that anyone would actually prefer symbols to English.” I prefer symbols to English. You are not alone. I write proofs for myself with Fitch diagrams. For myself because it is hard to post pictures on forums and IMHO not so many people understand that notation anyway. |