Simulating Accepting Networks of Evolutionary Processors with Filtered Connections by Accepting Evolutionary P Systems - Foundations on Natural and Artificial Computation - page 295

which can navigate in the network following a given protocol. Only that data
which is able to pass a filtering process can be communicated. This filtering pro-
cess may require to satisfy some conditions imposed by the sending processor,
by the receiving processor or by both of them. All the nodes send simultaneously
their data and the receiving nodes handle also simultaneously all the arriving
messages, according to some strategies, see [4,5]. The filtering process that is
to be considered here is regulated by some context conditions associated to the
edges of the graph. This is the model introduced in [2] under the name of accept-
ing network of evolutionary processors with filtered connections (ANEPFC). The
reader interested in a survey of the main results regarding ANEPFCs is referred
to [9].
P systems [13] were introduced as a computational model inspired by the
information and biochemical product processing of living cells through the use
of membrane communication. In most of the works about P systems, informa-
tion is represented as multisets of symbol/objects which can interact and evolve
according to predefined rules. Nevertheless, the use of strings to represent the
information and the use of rules to transform strings instead of multiset objects
have always been present in the literature of this scientific area. So, in his mostly
referred book [13], Gh. Paun overviews the use of string rules in P systems. Dif-
ferent variants of string-based P systems have been proposed along the time. We
can mention rewriting P systems [10], referred as membrane systems with worm
objects [1] in the case of genomic operations, insertion-deletion P systems [7] and
splicing P systems [12], among others. Observe that most of these models have
been used for language generation [11]. In [6,8], the proposal of hybrid P systems
introduces the use of contextual rules and Chomsky rules to achieve universality
by generating all the recursively enumerable languages.
In this work, we propose the use of evolutionary rules of string rewriting
in all regions of a P system. The idea is not new (see for instance [7]) but
our approach has two different main goals. First, the P systems considered here
define languages by an accepting process in contrast with the generating variants
widely considered so far in the area of membrane computing. Second, we show
that the membrane structure is indispensable for simulating the filtering process
in an ANEPFC. This is also in contrast with very many constructions of P
systems in which the membrane structure plays actually a very minor role, most
of them being reduced to just one membrane. The main part of this note is the
informal construction of an evolutionary P system simulating an ANEPFC with
emphasis on the membrane hierarchies of each region associated with a filtered
connection.
The structure of this work is as follows: In section 2 and 3 we recall the
definition of ANEPFCs and evolutionary P systems, respectively. Then, we in-
formally describe a construction of an evolutionary P system simulating a given
ANEPFC. More precisely, we discuss the evolutionary rules in each region and
the membrane structure associated with each filtered connection in the simulated
network.