3,377 reputation
1837
bio website jakitoimgeisterhaus.blogspot.…
location Munich, Germany
age 38
visits member for 3 years, 6 months
seen 1 hour ago

My past research interests included differential algebraic equations, nonlinear analysis and relations between symmetries and structural properties.

I recently investigated hierarchical structures, starting from group cohomology, continuing with semi-group theory and ending with lattices and universal algebra.


Nov
12
revised Which associative and commutative operations are defined for any commutative ring?
Added an appendix with a more intuitive explanation/description of the found operations
Nov
2
revised Which associative and commutative operations are defined for any commutative ring?
Now M.B. explained to me why the "if x is unit then f(x) else g(x)" construct is not natural...
Nov
1
revised Which associative and commutative operations are defined for any commutative ring?
edited body
Nov
1
revised Which associative and commutative operations are defined for any commutative ring?
fixed sign mistake and updated question with information from the comments
Oct
6
revised Are higher order logics substantially stronger than second order
Oh, I forgot that I wanted to say something about the last word property
Oct
5
revised Is multiplication in mixed radix numeral systems complicated?
edited tags
Aug
17
revised Why learn to solve differential equations when computers can do it?
fixed links
Aug
15
revised Which natural number predicates can be defined in Robinson arithmetic?
edited body
Jul
18
revised Can a biased physical random source be post-processed to control the bias?
OK, now I see my mistake in the description of the method
Jul
17
revised Can a biased physical random source be post-processed to control the bias?
Thought a bit about how this problem can be pragmatically addressed, and modified question accordingly
Jul
12
revised Which natural number predicates can be defined in Robinson arithmetic?
Now I understood the point which Asaf and Peter raised...
Jul
12
revised Which natural number predicates can be defined in Robinson arithmetic?
Added the requested clarification
Jul
10
revised Can a biased physical random source be post-processed to control the bias?
edited tags
Jul
10
revised Can a biased physical random source be post-processed to control the bias?
edited tags
Jun
9
revised Is there a (foundational) type theory with the features I'm looking for?
Add a reference to the place where Randall Holmes discusses TST, and to ARD Mathias' papers
Jun
3
revised How do I turn a “broken” plot into a smooth curve
propose a way to make the polynomial method more "reproducible, repeatable and programmable"
Jun
1
revised Can the divergence theorem be restricted to flat surfaces?
Talking about surfaces in the plane would be boring
May
19
revised Difference between bound and free variable
tried to incorporate comments by Mauro ALLEGRANZE
May
17
revised Non-i.i.d Empirical Risk Minimization
Mentioning only rejection sampling, but not also the composition method is not good...
May
12
revised A consistent first-order theory whose impredicative second-order variant is inconsistent
Fixed the question, to really ask the intended question. Also incorporated clarification into the question.