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Oct
8
answered how can we write abstract algorithms?
Oct
8
answered There is a table of the complexity of recursive algoritms?
Oct
8
reviewed Close How do epsilon-delta proofs work for limits at negative infinity?
Oct
8
answered $\mid$ in simply typed lambda calculus
Oct
8
answered Reflexivity: How can something be related to itself?
Oct
7
reviewed Leave Open Can someone help me solve this limits question?
Oct
7
reviewed Close How to prove an equivalent definition of injective?
Oct
7
reviewed No Action Needed Select r items from a set with multiplicity k and total items n.
Oct
7
reviewed Approve Is $x^8+1$ irreducible in $\mathbb{R}[x]$
Oct
7
reviewed Approve Is any relation which contains only one ordered pair transitive?
Oct
7
reviewed Close the division $14^{256}$ by $17$
Oct
7
comment Equivalence of Definitions for $T_1$
Hi, I added LaTeX formatting to your question. I'm not quite sure what you mean by "$N$ neighbourhoods" - do you mean that $\{x\} = \bigcap \{ N \mid N \in N_x \}$, were $N_x$ means the neighbourhoods of $x$?
Oct
7
revised Equivalence of Definitions for $T_1$
LaTeX formatting introduced
Oct
5
revised (Gamer Question) Really Hard Word Problem About Balancing
Chose more appropriate tags.
Sep
28
reviewed Leave Open Angle of rotation of a wheel over time
Sep
28
comment For what $a \in \Bbb R$ does $\neg(3a>21\implies a \leq 5)$ hold?
I suppose you know that that $\neg (A \implies B)$ if and only iff $A \land \neg B$? If you apply this and simplify $3a > 21$, you have an almost complete proof that this is equivalent to $a>7$...
Sep
27
accepted Equivalence of the definitions of “image” in category theory
Sep
27
comment Equivalence of the definitions of “image” in category theory
I use the definition that $f \circ \ker f = 0$ and if $f \circ k = 0$, there is a unique $g$ such that $g = \ker f \circ g$, similarily for cokernels. Note that I require my category to have zero morphisms.
Sep
27
asked Equivalence of the definitions of “image” in category theory
Sep
17
reviewed Edit Eigenvalues of a tridiagonal stochastic matrix