6,134 reputation
1623
bio website poisson.phc.unipi.it/~mossa
location Earth
age 26
visits member for 3 years, 2 months
seen 8 hours ago

I'm math student, in particular I'm interested in algebra, geometry, topology and category theory (especially higher dimensional category theory) and its application in mathematics.


Mar
1
comment Monomorphisms and Epimorphisms in the category of small categories
@user114885 I've added some stuff about epis too. Nonetheless I don't know if that can be enough for you. There's a claim (but I've not prove of it) for a possibile characterization of epis in $\mathbf {Cat}$.
Mar
1
revised Monomorphisms and Epimorphisms in the category of small categories
Address (partially) the last part of the question.
Feb
28
comment Monomorphisms and Epimorphisms in the category of small categories
I'd voluntarily left some of the details. Hope you don't mind.
Feb
28
answered Monomorphisms and Epimorphisms in the category of small categories
Feb
28
comment Gödel's Completeness Theorem and satisfiability of a formula in first-order logic
@MauroALLEGRANZA are you looking for a witness of indecidibility of first order logic?
Feb
26
reviewed Approve suggested edit on Why must this be a closed curve?
Feb
25
reviewed Edit suggested edit on Quotients of $\mathbb{Z}_2$ graded rings
Feb
25
revised Quotients of $\mathbb{Z}_2$ graded rings
Mistakes regarding the sets to which elements belong, that is the user has written $I$ instead of $R/I$
Feb
25
answered What to read alongside with Hatcher Algebraic Topology
Feb
24
reviewed Approve suggested edit on Statistics. Sampling data $\bar{X}$
Feb
22
reviewed Approve suggested edit on independent/dependent values at different frequencies and phases
Feb
22
reviewed Approve suggested edit on Calculus: tangents and limits
Feb
19
comment How do I prove that the function symbol $\circ$ is not a term by induction in the calculus?
then from the rule T2, since as you say $\circ \in S$, we have that $\circ$ is term. Otherwise you have to restrict rule T2 so that it can be applied just to term with $0$-ariety.
Feb
19
comment How do I prove that the function symbol $\circ$ is not a term by induction in the calculus?
What do you mean by $\circ$, is a defined term or is part of the alphabeth (which I suppose is $S$)? In the second case from you rules it should follow that $\circ$ is a term since for every $f \in S$ it follows that $f$ is term (T2), since in this rule there's no restriction on the applicability. Hope this helps.
Feb
15
comment What are morphisms in the category of sets $\mathbf{Set}$?
@Alexey you're welcome.
Feb
15
comment What are morphisms in the category of sets $\mathbf{Set}$?
@Alexey I do: "Category theory starts... ... Each arrow $f \colon X \to Y$ represent a function; that is, a set $X$, a set $Y$, and a rule $x \mapsto fx$ which ..." at page 1.
Feb
15
comment What are morphisms in the category of sets $\mathbf{Set}$?
For the function is said in the introduction of "Category theory for Working mathematician".
Feb
15
answered What are morphisms in the category of sets $\mathbf{Set}$?
Feb
12
comment If $N$ is an $R/I$-submodule of $M$ can we view $N$ as an $R$-submodule of $M$?
@Edgar $N$ is a $R/I$-submodule of the $R/I$-module...?
Feb
8
reviewed Approve suggested edit on Suggestions on how to verify this partial differential equation solution