2,223 reputation
1324
bio website math.berkeley.edu/~sramesh
location Berkeley, CA
age 28
visits member for 4 years, 2 months
seen Apr 13 at 20:50
I am a graduate student in the Logic program at Berkeley, broadly interested in categorical logic and foundations of mathematics, as well as in applications of category theory to the semantics of programming languages.

Aug
31
comment Intuitionistic consistency of surjection from naturals to reals
Thanks! For what it's worth, the part of my self-convincing that doesn't go through must be the idea that subsingletons of reals surject onto reals (I was imagining this could work by sending a subset of the reals to its least upper bound (I suppose by "reals" here, I really mean something like $[0, 1]$)); had that been so, an injection from $\mathbb{R}$ to $\mathbb{N}$ could be reversed into a surjection from $\mathbb{N}$ to $\mathbb{R}$.
Aug
31
comment Intuitionistic consistency of surjection from naturals to reals
Ah, I was right to be unconvinced by my self-convincing, then... :)
Aug
31
revised Intuitionistic consistency of surjection from naturals to reals
deleted 1 characters in body
Aug
31
asked Intuitionistic consistency of surjection from naturals to reals
Aug
22
comment What's a groupoid? What's a good example of a groupoid?
I wouldn't call this incoherent, just terminologically muddled. Read "morphism" in the place of "functor" and "transformation", and understand that "there is... an inverse" means exactly what it should. This answer no doubt comes from a place of actually knowing what a groupoid is; it just fails to clearly communicate that.
Aug
15
awarded  Nice Answer
Aug
2
comment Are all the theorems true?
(I suppose I should point out, in case you are not aware, that the reason ZFC + "ZFC is inconsistent" is equiconsistent with ZFC is because of Goedel's second incompleteness theorem)
Aug
2
comment Are all the theorems true?
The example I gave is also not restricted to PA. It works in exactly the same way for any base theory capable of speaking of itself; e.g., if ZFC is consistent, then ZFC + "ZFC is inconsistent" is consistent but not "good".
Aug
2
comment Are all the theorems true?
If question 3 is restricted to theories which are "good", then of course they will be consistent as well... consistency is part of your definition of "goodness"! What could question 3 be asking about, if not the question of whether there is a consistent, non-"good" theory?
Aug
1
answered Are all the theorems true?
Jul
10
comment Fiction books about mathematicians?
Mathematicians should not do, and certainly not enjoy, anything other than mathematical research, lest they give themselves away as human beings with a variety of interests and not a 100% devotion to just the one.
Jun
16
comment Ingenuity in mathematics
[Pedantic note: 0 and n - 1 can both occur if there is only 1 person at the party. But perhaps it is implicit in "party" that there are at least two people.]
Jun
9
comment What are good non-English languages for mathematicians to know?
Knowing some programming language well is probably useful. But C, specifically, needn't be it...
Jun
1
comment Is complement of LL(k) grammar context free?
en.wikipedia.org/wiki/LL_parser
May
23
awarded  Enlightened
May
23
awarded  Nice Answer
May
2
comment existence of a field that has a non surjective ring homomorphism
I usually leave only comments rather than answers, to bypass the silly reputation system. But for once, I thought, let me post an actual answer. And what's the result? A bunch of responses about somebody else's answer-posted-as-comment. :)
May
2
comment existence of a field that has a non surjective ring homomorphism
Ah, good point! I should have thought of that. I kept implicitly thinking $\mathbb{R}$ was algebraically closed...
May
2
revised existence of a field that has a non surjective ring homomorphism
D'oh!
May
2
answered existence of a field that has a non surjective ring homomorphism