The “equal last” predicate for words on infinite alphabets and classes of multitape automata
نویسندگان
چکیده
Along with the usual predicates “prefix” and “equal length”, the predicate “equal last letter” leads to a first order theory of the free infinitely generated monoid whose definable relations are related to the algebra of relations recognized by different types of multitape automata which are natural extensions of the famous Rabin-Scott multitape automata and the so-called synchronous automata. We investigate these classes of automata and solve decision isssues concerning them.
منابع مشابه
Finite n-tape automata over possibly infinite alphabets: Extending a theorem of Eilenberg et al
Eilenberg, Elgot and Shepherdson showed in 1969, [9], that a relation on finite words over a finite, non-unary alphabet with p letters is definable in the first order logic with p + 2 predicates for the relations equal length, prefix and last letter is a (for each letter a ∈ Σ) if and only if it can be recognized by a finite multitape synchronous automaton, i.e., one whose read heads move simul...
متن کاملOn a Class of P Automata as a Machine Model for Languages over Infinite Alphabets
We show how P automata having a finite description and working with a finite object-alphabet can be used to describe languages over countably infinite alphabets. We propose to relate the language classes characterized by different types of P automata to some of the existing characterizations of language classes over infinite alphabets, and give an upper bound for the class of languages accepted...
متن کاملReviews of Papers in the Computer Field
is defined in terms of the predicate calculus and involves formulas without quantifiers. Let TM, LBA, MTA2 stand for Turing machines, linear-bounded automata, and two-way multitape finite automata, respectively. Let TRO, TR,, TR2 denote classes of predicate formulas involving transitive closure. The subscript d stands for deterministic. The main results in the paper are the six equalities in th...
متن کاملLattice Automata: A Representation for Languages on Infinite Alphabets, and Some Applications to Verification
This paper proposes a new abstract domain for languages on infinite alphabets, which acts as a functor taking an abstract domain for a concrete alphabet and lift it to an abstract domain for words on this alphabet. The abstract representation is based on lattice automata, which are finite automata labeled by elements of an atomic lattice. We define a normal form, standard language operations an...
متن کاملVariable Automata over Infinite Alphabets
Automated reasoning about systems with infinite domains requires an extension of automata, and in particular, regular automata, to infinite alphabets. Existing formalisms of such automata cope with the infiniteness of the alphabet by adding to the automaton a set of registers or pebbles, or by attributing the alphabet by labels from an auxiliary finite alphabet that is read by an intermediate t...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2008