Filters








1,965 Hits in 3.5 sec

Expressiveness of Process Algebras

Joachim Parrow
2008 Electronical Notes in Theoretical Computer Science  
The negative results are for encodings which are homomorphic, preserve barbs and have an operational correspondence. [11] study the subset of the π-calculus where all prefixes are replicated.  ...  It is compositional, and homomorphic in all operators except choice. The encoding is proved weakly coupled equivalent (a version of weak bisimulation), and preserves divergence properties.  ... 
doi:10.1016/j.entcs.2008.04.011 fatcat:qoqzqcroifernk3lswiun3kjam

Parikh-reducing Church-Rosser representations for some classes of regular languages [article]

Tobias Walter
2017 arXiv   pre-print
Since δ is primitive, this implies gcd(|δ| , |δ|) = |δ|. Sinceδ is a prefix of x, this yields thatδ is a power of δ which implies δ =δ by primitivity ofδ.  ...  As such rules preserve the prefixes and suffixes of length 3n, the word v must have the correct form. In the case of ωuω ′ =⇒ T ∆ v, some rule δ t+n → δ t was applied.  ... 
arXiv:1703.10056v1 fatcat:sbd6rf3jrbfpxjwemqjfkiio6y

H-bounded and semi-discrete languages

M. Kunze, H.J. Shyr, G. Thierrin
1981 Information and Control  
(d) Embedding order is preserved under homomorphisms.  ...  Now consider the canonical homomorphism ~,:F*~22", which erases the letter e. Since q~(L)=b22* is not semi-discrete, we see that homomorphisms do not preserve semi-discreteness in general.  ... 
doi:10.1016/s0019-9958(81)90253-9 fatcat:56yhkvdt3fbeziz6o32tgf7rke

Calculating Parallel Programs in Coq Using List Homomorphisms

Frédéric Loulergue, Wadoud Bousdira, Julien Tesson
2016 International journal of parallel programming  
The framework is illustrated on the maximum prefix sum problem.  ...  In this paper we present a new core version of SyDPaCC for the development of parallel programs correct-by-construction using the theory of list homomorphisms and algorithmic skeletons implemented and  ...  This is transparent to the user as there are instances of the NonEmpty class that state that prefix always returns a non-empty list and that map preserves non-emptiness. mps spec is not leftwards.  ... 
doi:10.1007/s10766-016-0415-8 fatcat:erfn3kiztvcvhj2ksskgrzttyy

Page 86 of Mathematical Reviews Vol. , Issue 97A [page]

1997 Mathematical Reviews  
Let *V be an enlargement of the standard universe V; as usual, we use the prefix * to indicate nonstandard notions.  ...  , *homomorphic images, and internal direct products.  ... 

Dense subsets in semigroups

Yuanlan Zhou, Yun Liu
2013 International Mathematical Forum  
This article covers a theory of dense subsets in general semigroups, including basic algebraic properties of dense and disjunctive subsets, characterizations of dense subset preserving homomorphisms and  ...  For example a homomorphism ϕ : A * → B * is called a code (resp. primitive word)-preserving homomorphism if ϕ maps all codes (resp. primitive words) over A to codes (resp. primitive words) over B (see  ...  Let S and T be any two semigroups and ϕ be a homomorphism from S to T . Then ϕ is dense subset preserving if and only if ϕ is complete subset preserving.  ... 
doi:10.12988/imf.2013.39181 fatcat:bt65xskhqva4tkknofjdxzkd3a

Primitive partial permutation representations of the polycyclic monoids and branching function systems

Mark V. Lawson
2009 Periodica Mathematica Hungarica  
We characterise the maximal proper closed inverse submonoids of the polycyclic inverse monoids, also known as Cuntz inverse semigroups, and so determine all their primitive partial permutation representations  ...  Zhitomirskiy for discussions on what constitutes a primitive partial permutation representation of an inverse semigroup.  ...  All inverse semigroups will have a zero and we shall assume that homomorphisms are homomorphisms that preserve the zero.  ... 
doi:10.1007/s10998-009-10189-2 fatcat:e43jje7zyvec7m7zdxsjqgdloe

Homogeneous Thue systems and the Church-Rosser property

Ronald V Book
1984 Discrete Mathematics  
÷l are prefixes of r, either rl = rq+~ or rl is a proper prefix of rq+~ or rq+l is a proper prefix of r 1.  ...  Case 1. w is primitive and w has no overlap. Case 2. w is imprimitive and p(w) has no overlap. Case 3. w is primitive and w has overlap. Proof.  ... 
doi:10.1016/0012-365x(84)90177-8 fatcat:fbzpfqmldfaodbgivesxnffyfi

Checking Properties within Fairness and Behavior Abstractions [article]

Ulrich Ultes-Nitsche, Pierre Wolper
2001 arXiv   pre-print
between behavior abstraction and satisfaction within fairness is studied and it is proved that satisfaction of properties within fairness can be verified on behavior abstractions, if the abstraction homomorphism  ...  We show that weakly continuation-closed homomorphisms preserve exactly properties satisfied within fairness.  ...  PRESERVATION OF LINEAR PROPERTIES Before turning to the preservation of properties satisfied within fairness by weakly continuation-closed homomorphisms, we need some general results about abstraction  ... 
arXiv:cs/0101017v1 fatcat:msgi5xsfhbbtfl465nsivbblc4

Separation of Synchronous and Asynchronous Communication Via Testing

Diletta Cacciagrano, Flavio Corradini, Catuscia Palamidessi
2006 Electronical Notes in Theoretical Computer Science  
In this sense, it turns out that, under some general conditions, no encoding of output prefix is able to preserve the must testing.  ...  We investigate whether the above encodings preserve De Nicola and Hennessy's testing semantics.  ...  Theorem 6.2 Let [[·]] be an encoding that satisfies: 1. compositionality w.r.t. input and output prefixes, 2. homomorphism w.r.t. τ prefix, Proof: Suppose, by contradiction, that [[·]] is must -preserving  ... 
doi:10.1016/j.entcs.2006.05.009 fatcat:ymammbux2fh6bhtf46xwnnn2g4

The decision problem for the logic of predicates and of operations

Yu. Sh. Gurevich
1969 Algebra and Logic  
Gurevich UDC518.5 INTR OD UC TI ON Most work on the decision problem for the logic of predicates belongs to the class of preliminary formulas, posed in a way limited to prefixes and predicate variables  ...  Conversely, suppose the prefix ~ (~nad W). The word ~7=8o,*...~Br, z for some Bl'~? (r,',adW) . The operations ~ --~F~ preserve the property of the word's having this resolution.  ...  (r-,.zod W) is primitively recursive. 2. Suppose ~ and /Vz run through the names, indicated in Definition 11, of all possible closed sets of prefixes.  ... 
doi:10.1007/bf02306690 fatcat:w7dqxgsjjbb27hfbqs2ei4fnpu

Remarks on recognizable subsets and local rank [article]

Christopher D. C. Hawthorne
2019 arXiv   pre-print
(a * 0 b 0 ∪ · · · ∪ a * n−1 b n−1 ) c for primitive a 0 , . . . , a n−1 and b i a proper prefix of a i . Proof.  ...  Suppose |a * a 0 ∩ b * b 0 | ≥ 2 with a, b primitive, a 0 a proper prefix of a, and b 0 a proper prefix of b. Then a = b and a 0 = b 0 . Proof. Suppose |a * a 0 ∩ b * b 0 | ≥ 2.  ...  The syntactic monoid of a regular language A is the smallest monoid F for which there exists a homomorphism α : Σ * → F witnessing the recognizability of A; see [7, Section IV.4.1] for details.  ... 
arXiv:1803.07234v2 fatcat:t3hjxt47qreorgoq3sviasqqdq

Separation of synchronous and asynchronous communication via testing

D. Cacciagrano, F. Corradini, C. Palamidessi
2007 Theoretical Computer Science  
In this sense, it turns out that, under some general conditions, no encoding of output prefix is able to preserve the must testing.  ...  We investigate whether the above encodings preserve De Nicola and Hennessy's testing semantics.  ...  Theorem 6.2 Let [[·]] be an encoding that satisfies: 1. compositionality w.r.t. input and output prefixes, 2. homomorphism w.r.t. τ prefix, Proof: Suppose, by contradiction, that [[·]] is must -preserving  ... 
doi:10.1016/j.tcs.2007.07.009 fatcat:zjhb2p2uojeipe5xenv526l2yy

On Words with the Zero Palindromic Defect [chapter]

Edita Pelantová, Štěpán Starosta
2017 Lecture Notes in Computer Science  
Primitive morphisms that preserve the set of rich words are included in a larger set of morphisms having infinitely many palindromic factors in their fixed points.  ...  In particular, any fixed point of a primitive morphism which preserves the set of rich words must be rich as well. In this point of view the following question is also important.  ... 
doi:10.1007/978-3-319-66396-8_7 fatcat:xs2onkpeqfbexfgydccubuznty

Regular Languages Are Church-Rosser Congruential [chapter]

Volker Diekert, Manfred Kufleitner, Klaus Reinhardt, Tobias Walter
2012 Lecture Notes in Computer Science  
By primitivity of η this implies that η 1 is empty and by primitivity of δ we obtain ζ = η. This implies |δ| = |η| and since η t+n is a factor of δ t+n we obtain that η = δ.  ...  Thus, there is a conjugate ζ = η r η 1 of δ such that η 1 is a proper prefix of η and ζ 2 is a prefix of η t . By canceling the prefix η r we see that η 1 η is a prefix of η 2 .  ...  If L is regular, then there exists a homomorphism ϕ : A * → M recognizing L. By Theorem 5.1 there exists a Church-Rosser system S of finite index such that ϕ factorizes through S.  ... 
doi:10.1007/978-3-642-31585-5_19 fatcat:42x3d3j6h5gy7ojsei7jbogqju
« Previous Showing results 1 — 15 out of 1,965 results