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4 votes
0 answers
122 views

Are semilinear sets piecewise periodic?

I wanted to check my understanding of semilinear sets before I give a talk on them, and I haven't been able to find this exact perspective in any of the sources I've read through. Is it correct, and ...
TomKern's user avatar
  • 429
2 votes
1 answer
133 views

What is the cardinality of the set of Dyck natural numbers of semilength $k$?

In arXiv:2102.02777 ("Recursive Prime Factorizations: Dyck Words as Numbers"), I show that there is a 1:1 correspondence between $\mathbb{N} = \{0,1,2,3,4,\ldots\}$ and $\mathcal{D}_{r_{\...
JustAsking's user avatar
-1 votes
1 answer
125 views

Prove using Dyck naturals: for $n \in \mathbb{N}_{+}$ and big enough $k \in \mathbb{N}_{+}$, $p_{k-1} < \cdots < np_{k-a_{n}}$ (a is A073093)

While conducting research in connection with arXiv:2102.02777 ("Recursive Prime Factorizations: Dyck Words as Numbers"), I noticed certain interesting patterns, one of which inspired the ...
JustAsking's user avatar
6 votes
1 answer
562 views

How can I catalog these generalized Collatz problems?

The Collatz conjecture can be expressed in terms of a ruleset in the language $\{x,+,1,\rightarrow,;\}$: $x + x + 1 \rightarrow x+x+x+1+1;$ $x + x \rightarrow x;$ Whenever a number matches the LHS ...
Dan Brumleve's user avatar
  • 2,302
-1 votes
2 answers
2k views

Any grammar for the language $L =a^p$, $p$ is prime number of $\mathbb{N}$

Any grammar for the language $$L =a^p,\text{ $p$ is prime and }p\in \mathbb{N}?$$ Is such a grammar related to any question of number theory like RH or the conjecture of twin primes?
XL _At_Here_There's user avatar
0 votes
1 answer
158 views

any given c.e.set has number M whose power bounds the corresponding elements of S?

For S ,any given c.e.set,does there exist a M (integer) and a partially computable function outputing every element of S the c.e.set ,such that $\forall x\in S,\exists n x=f(n)$ and $x=f(n)\leq ...
XL _At_Here_There's user avatar
19 votes
3 answers
1k views

Status of an open problem about semilinear sets

In his book "The Mathematical Theory of Context-Free Languages" (1966), Ginsburg mentioned the following open problem: Find a decision procedure for determining if an arbitrary semilinear set is a ...
Tara Brough's user avatar