244 reputation
15
bio website schlemmersoft.de
location Dresden
age 37
visits member for 3 years, 5 months
seen Jun 1 at 10:33
I'm a Ph.D. concerned with mathematical music theory, ordered groups, lattices, formal concept analysis and interested in algebra.

May
29
comment Equality-preserving embeddings of finite trees
I don't understand your question. Isn't it true that every finite subset of the natural numbers is a special case of a finite set?
May
17
awarded  Yearling
May
8
comment Galois Connections: algorithmic generation
You are welcome. Today I got a literature suggestion about this topic (see edit).
May
8
revised Galois Connections: algorithmic generation
Added an article suggestion
May
3
answered Galois Connections: algorithmic generation
Mar
22
answered Has the single sorted case of formal concept analysis been investigated?
Jan
17
revised What is known about orbifolding ordered groups and sets? Who has been involved? Links to Lee metrics?
Added a further explanation to the question.
Jan
17
awarded  Commentator
Jan
17
comment What is known about orbifolding ordered groups and sets? Who has been involved? Links to Lee metrics?
A better description of $Λ$ would be: It describes the action that is necessary to map a tuple into the transversal if its first place is already there.
Jan
17
awarded  Student
Sep
18
comment Does the notion of graphs with vertex multiplicity exist?
A similar construction has been called binary relation orbifold (Borchmann, Daniel: Context Orbifolds, Diploma Thesis, TU Dresden, 2009, link).
Sep
17
comment Conditions for a group to be lattice-ordered
I think you should contact one of the authors of the corresponding papers and ask them if they can help you. It is a very special branch of mathematics and propably of the contributers are not active participants of MO.
Sep
15
comment Conditions for a group to be lattice-ordered
@BorisNovikov Have a look at my answer, Statement 1 (it was added before I saw your comment). The linear order that you constructed using Szpilrajn's lemma does not fulfil Xodaraps conditions. Thus, it is not a counterexample.
Sep
15
answered Conditions for a group to be lattice-ordered
Sep
15
comment Conditions for a group to be lattice-ordered
The first implication in the proof of 2) does not hold. As in any right-ordered group the implications $x≤y ⇒ xz≤yz$ holds but not necessarily $x≤y⇒zx≤zy$. On the other hand Szpilrajn is not enough to construct a contradiction as $(\mathbb Z,≤)×(\mathbb Z,≤)$ has also linear order extension $≤_l$ that leads to $(x∨_ly)z=yz≠xz=xz∨_lyz$ for some $x,y,z$.
Sep
14
comment Conditions for a group to be lattice-ordered
Is every right-ordered group with a lattice order already an ordered group? If not there are counterexamples as the implications $x≤1 ⇒ xz≤z$ and similarly for $x≥1$ is a conclusion of being right-ordered. Otherwise it would be sufficient to prove that it is a right-ordered group.
Sep
13
revised Self-containing graphs
Some further consideration of loops.
Sep
13
comment Self-containing graphs
If $H$ is a proper subgraph of some finite graph $G$ then $G$ there is no injective mapping from the set of nodes of $G$ into the set of nodes of $H$.
Sep
12
revised Self-containing graphs
forgot to consider loops
Sep
12
answered Self-containing graphs