5,062 reputation
1932
bio website mpi-sws.org
location Kaiserslautern, Germany
age 32
visits member for 2 years, 5 months
seen 14 hours ago

PhD student at MPI-SWS.


Mar
26
reviewed Approve suggested edit on Invertible matrices and row equivalence
Mar
25
reviewed Approve suggested edit on About the definition of fixed-point combinators
Mar
23
comment Why is this Goldbach's Conjecture Proof Wrong?
As a first comment, I don't understand what your proof of Lemma 2 shows. In particular, how is "L cannot be a prime" a contradiction?
Mar
17
answered Program with no intermediary states
Mar
17
comment Program with no intermediary states
Oh, wait. You may need higher-order functions; see the answer.
Mar
17
comment Program with no intermediary states
As long as you can give effective semantics to your model/programming language, yes. Does this answer your question?
Mar
17
comment Program with no intermediary states
To be more concrete, suppose you have big-step semantics for an imperative programming language without function calls. Then for each statement, we get a (computable) function mapping a variable context to a variable context. Chain all these functions, and you have a representation of your program as a sequence of function applications.
Mar
17
comment Program with no intermediary states
What is your computation model? If you allow any model and provide denotational semantics, the answer is "trivially, yes": Just take the function induced by the denotational semantics. Edit: This also works with other formal semantics, e.g., small-step operational semantics or natural semantics.
Mar
13
reviewed Approve suggested edit on Showing a Problem Is Undecidable
Mar
13
awarded  Proofreader
Mar
13
reviewed Approve suggested edit on General versions of (Second part of) Fundamental Theorem of Calculus
Mar
8
comment What is the meaning of $M \models \varphi$?
That is the right interpretation.
Mar
8
answered What is the meaning of $M \models \varphi$?
Mar
5
awarded  Yearling
Feb
28
comment Given S is non-empty and sup(S)=inf(S), prove that the set S has only one element.
@MPW: I know, but I wanted to point out a gap in the proof.
Feb
28
comment Given S is non-empty and sup(S)=inf(S), prove that the set S has only one element.
A minor thing: What if $S = \varnothing$?
Feb
20
comment Knuth-Bendix completion algorithm: word problem
I'm not quite sure what you mean be "see certain structures". Are you asking how Knuth-Bendix is implemented, or do you want to know how to find the complete set of normal forms?
Feb
9
comment Buchberger's criterion to show Grobner basis for linear forms
Yes, that's the idea here.
Feb
9
comment Buchberger's criterion to show Grobner basis for linear forms
Right, scratch the "strictly". If its support is contained, you can reduce by $g$, yielding $E$ (and if you do it right, you can reduce in such a way the the leading coefficient of $D$ is reduced to zero), thereby getting a polynomial that is smaller according to the monomial ordering. By properties of the reduction, $E \in L$ again, so you can repeat the process. Because of well-foundedness, this can only happen finitely many times. What would the normal form look like, when it's in $L$?
Feb
9
comment Buchberger's criterion to show Grobner basis for linear forms
Didn't you want to show this for $k \neq l$? Anyway, if $k = l$, you have found a critical pair. Since $L$ is an ideal, certainly $D := x_l A -x_k B \in L$. By definition of $S$, there's some $g \in S$ whose support is strictly contained in that of $D$. What can you deduce from this?