TL;DR: The problem of deciding validity in the theory of equality is shown to be complete in polynomial-space, and close upper and lower bounds on the space complexity of this problem are established.

TL;DR: New proofs of two properties of the polynomial-time hierarchy are given, where the classes in the hierarchy are characterized using polynomially bounded quantifiers.

TL;DR: The reachability set for vector addition systems of dimension less than or equal to five are shown to be effectively computable semilinear sets, and reachability, equvalence and containment are decidable up to dimension 5.

TL;DR: If X and Y are n element sets of real numbers, then the n 2 element set X + Y can be sorted with O ( n 2 ) comparisons, improving upon the n2 log 2 n bound established by Harper et al.

TL;DR: Two algorithms are proved to compute the closure of a matrix oven any closed semiring using a generalization of algorithms by Warshall, Floyd and Kleene and a generalized version of Dijkstra algorithm.

TL;DR: The question to decide whether a given Petri net is consistent, Mo-reversible or live is reduced to the reachability problem in a unified manner.

TL;DR: The main result can be described as follows: for every e 0 one can construct a polynomial-time algorithm for each of the above problems such that the ratio of the value of the objective function by this algorithm and the optimal value is bounded below by 1 - e.

TL;DR: A general lower bound on the minimal number of additions in monotone, rational computations is proved, which implies that anymonotone rational computation of the n th degree convolution at least requires n 2 − 2 n + 1 additions.

TL;DR: This paper deals with the problems of applying a unification procedure in a mechanization of the full type theory and an extensive proof of completeness of the algorithm is presented.

TL;DR: A well-known theorem of Eerstel which gives a necessary condition for positiveness is also essentially sufficient and makes it possible to answer some problems appearing in EileGerg and to decide the -rationality of a -rational sequence.

TL;DR: It is shown that the languages recognized by two-way deterministic FAM's are of tape complexity log n and time complexity n 3 .

TL;DR: It is shown that Valiant's partial procedure for equivalence can be made constructive and the time complexity of the algorithm is bounded by a double exponential function of the size of the input.

TL;DR: This paper provides a method of “decomposing” a subclass of ET0L languages into deterministic ET1L languages, which allows one to use every known example of a language which is not a deterministicET0L language to produce languages which are not ET0l languages.

TL;DR: Translational lemmas are stated in a general framework and then applied to specific complexity classes, and necessary and sufficient conditions are given for every set accepted by a Turing acceptor which operates in linear or polynomial time.

TL;DR: In this article, it is argued that both call-by-value and callby-name mechanisms yield the least fixed points of the functionals determined by the bodies of the procedures concerned.

TL;DR: It is shown that the tape bounded complexity classes of languages over single letter alphabets (sla) are closed under complementation and it immediately follows that the set of primes in unary notation, P, requires exactlyLog n tape for its recognition and every infinite subset of P requires at least log n tape.

TL;DR: The surface tree languages obtained by top-down finite state transformation of monadic trees are exactly the frontier-preserving homomorphic images of sets of derivation trees of ETOL systems.

TL;DR: It is shown that the sequence equivalence problem is decidable for every smooth family of DOL- systems, and a large subfamily of D OL-systems, called simple DOLs, is shown to be smooth.

TL;DR: It is proved that there exist many structurally different optimal computations for Eq (n) and the smallest number of arbitrary binary Boolean operations that are used in any Boolean computation for F is L(Eq(n) = 2n −3, L (and(n), nor(n))=2n−2.

TL;DR: A context-free language is shown to be equivalent to a set of sentences describable by sequences of strings related by finite substitutions on finite domains, and vice-versa, and a necessary and sufficient version of the Classic Pumping Lemma is established.

TL;DR: Four methodological results are given to help in studying the sub-families of the context-free languages family by derive some simple (already known) results.

TL;DR: This work studies the class of families admitting such a function S, as well as some of its subclasses defined by imposing certain restrictions on S (these restrictions reflect the structure of the storage medium to be used for storing a file).

TL;DR: By a general degree argument V. Strassen has obtained sharp lower bounds for the number of multiplications/divisions necessary to compute the elementary symmetric polynomials and for related problems.

TL;DR: The following languages are shown to be uniformly erasable: (i) the family of one-counter languages; and (ii) every family ofOne-letter languages.

TL;DR: The class of all languages which are acceptable in exponential time is equal to the class ofall languages generated by context-sensitive grammars with context-free control sets.

TL;DR: It is shown that the equivalence problem for linear s-grammars is decidable in polynomial time.

TL;DR: Effective findability of zeros of Z -rational functions is shown to imply solvability of the equivalence problem as well as the ultimate equivalence problems for HD0L sequences the morphisms of the generatingHD0L systems of which have Parikh matrices with eigenvalues of the form r e.