Generalized Hex and logical characterizations of polynomial space

Generalized Hex and Logical Characterizations of Polynomial Space We Consider a Particular Logical Characterization of the Complexity Class Pspace Using Rst-order Logic, with a Built-in Successor Relation, Extended

We answer a question posed by Makowsky and Pnueli and show that the logic (HEX) FO s ], where HEX is the operator (i.e., uniform sequence of Lindstrr om quantiiers) corresponding to the well-known PSPACE-complete decision problem Generalized Hex, collapses to the fragment HEX 1 FO s ] and, moreover, that this logic has a particular normal form which results in the problem HEX being complete for...

Characterizations of Certain Marshall-Olkin Generalized Distributions

Several characterizations of Marshall-Olkin generalized distributions, introduced by Gui (2013) and by Al-Saiari et al. (2014) are presented. These characterizations are based on: (i) a simple relationship between two truncated moments ; (ii) the hazard function.

Logical Characterizations of Complexity Classes

Logical and Algebraic Characterizations of Rational Transductions

Rational word languages can be defined by several equivalent means: finite state automata, rational expressions, finite congruences, or monadic second-order (MSO) logic. The robust subclass of aperiodic languages is defined by: counter-free automata, star-free expressions, aperiodic (finite) congruences, or first-order (FO) logic. In particular, their algebraic characterization by aperiodic con...

Characterizations of Generalized Quadrangles by Generalized Homologies

Let S= (P, B, I) be a generalized quadrangle of order (s, t). For X, y E P, X+ y. let X(x, y) be the group of all collineations of S fixing x and y linewise. If ZE (4 YJL> then the set of all points incident with the line xz (resp. y;) is denoted by z(resp. 3. The generalized quadrangle S = (P, B, I) is said to be (x, y)-transitive, x+ y, if X(x, y) is transitive on each set Z{x, z} and jZ’-{ y...