bio  website  ncatlab.org/nlab/show/… 

location  Adelaide, Australia  
age  30  
visits  member for  4 years, 11 months 
seen  20 hours ago  
stats  profile views  9,462 
Pure mathematician interested in category theory and foundations.
21h

comment 
A metric on $S^{2}$
math.cornell.edu/~hatcher/3M/3Mdownloads.html 
Oct 17 
comment 
A fixed point problem about the iterated mappings
I suggest editing previous versions of this theorem directly, and asking for it to be reopened on meta.mathoverflow.net, rather than asking a new question. As it stands, this question is still not wellformed. For instance, what you do mean by 'mapping'? Following on Alex's comment, does $\delta$ depend on $l$? 
Oct 15 
comment 
Statistics, probability
Where did this question arise? Consult our FAQ for reasons this is closed, in the event that this happens. 
Oct 13 
awarded  Nice Question 
Oct 10 
comment 
Forcing is intuitionistic
Because forcing is really the internal language of some topos, and topos logic is in general intuitionistic? It's a special case that you end up with Boolean logic because for ZFC applications you take what is called the 'double negation topology'. Other sorts of forcing are possible (e.g. Heytingvalued models in material language) 
Oct 10 
comment 
Asking for an English version of a paper
If the OP isn't at such an institution, there's always document delivery/interlibrary loan. 
Oct 8 
comment 
Is there a general notion of a subobject generated by a subset in any concrete category?
You probably want the notion of a topological concrete category (see below remark 1 in ncatlab.org/nlab/show/topological+concrete+category) or slightly weaker, asking instead for lifts of monics, rather than arbitrary families of maps. 
Oct 3 
accepted  Generator of $\pi_3(SU(4))$ in MimuraToda 
Oct 3 
answered  Generator of $\pi_3(SU(4))$ in MimuraToda 
Sep 30 
awarded  Explainer 
Sep 30 
comment 
What is the *smallest* number used in a mathematical paper?
I removed the $...$ from the title.

Sep 30 
revised 
What is the *smallest* number used in a mathematical paper?
Removed inappropriate use of maths mode in title 
Sep 27 
comment 
whatif.xkcd.com: stabbing (simply connected) regions on the 2sphere with few geodesics
@MoritzFirsching well, that rules out doing this for the whole world, then, by the existence of enclaves (and, if one wants to be controversial, disputed territories). 
Sep 27 
comment 
on the center of a Lie group
...assuming their library has that book. 
Sep 26 
revised 
Cancellation and splitting theorems for vector bundles etc over schemes
added 156 characters in body 
Sep 26 
asked  Cancellation and splitting theorems for vector bundles etc over schemes 
Sep 21 
comment 
codimension one minimizing verifolds
Welcome to MO ! 
Sep 19 
accepted  Sheaf of isogenies representable? 
Sep 19 
comment 
Sheaf of isogenies representable?
I've been pondering whether this has been possible for a long, long time, but procrastinating as I thought it something completely off the wall. So thanks! 
Sep 19 
comment 
Sheaf of isogenies representable?
Awesome! So the sheaf $\underline{Isog}_S(E_1,E_2)$ of isogenies is represented by a subscheme of $Hom_S(E_1,E_2)$? 