First-order definability and algebraicity of the sets of annihilating and generating collections of elements for some relatively free solvable groups.
First-order properties of trees, star-free expressions, and aperiodicity
Fixed points and self-reference.
Fixed points of fuzzy monotone maps
The existence of fixed points for monotone maps on the fuzzy ordered sets under suitable conditions is proved.
Fixed points of fuzzy monotone multifunctions
Under suitable conditions we prove the existence of fixed points of fuzzy monotone multifunctions.
Fixed Points Of Monotone Multifunctions In Partially Ordered Sets
Fixed points theorems for -fuzzy monotone maps.
Fixed points theorems of non-expanding fuzzy multifunctions
We prove the existence of a fixed point of non-expanding fuzzy multifunctions in -fuzzy preordered sets. Furthermore, we establish the existence of least and minimal fixed points of non-expanding fuzzy multifunctions in -fuzzy ordered sets.
Fixed points with respect to the L-slice homomorphism
Given a locale and a join semilattice with bottom element , a new concept called -slice is defined,where is as an action of the locale on the join semilattice . The -slice adopts topological properties of the locale through the action . It is shown that for each , is an interior operator on .The collection is a Priestly space and a subslice of -. If the locale is spatial we establish an isomorphism between the -slices and . We have shown that the fixed set of ,...
Fixpoint alternation : arithmetic, transition systems, and the binary tree
Fixpoint alternation: arithmetic, transition systems, and the binary tree
We provide an elementary proof of the fixpoint alternation hierarchy in arithmetic, which in turn allows us to simplify the proof of the modal mu-calculus alternation hierarchy. We further show that the alternation hierarchy on the binary tree is strict, resolving a problem of Niwiński.
Fixpoints, games and the difference hierarchy
Drawing on an analogy with temporal fixpoint logic, we relate the arithmetic fixpoint definable sets to the winning positions of certain games, namely games whose winning conditions lie in the difference hierarchy over . This both provides a simple characterization of the fixpoint hierarchy, and refines existing results on the power of the game quantifier in descriptive set theory. We raise the problem of transfinite fixpoint hierarchies.
Fixpoints, games and the difference hierarchy
Drawing on an analogy with temporal fixpoint logic, we relate the arithmetic fixpoint definable sets to the winning positions of certain games, namely games whose winning conditions lie in the difference hierarchy over . This both provides a simple characterization of the fixpoint hierarchy, and refines existing results on the power of the game quantifier in descriptive set theory. We raise the problem of transfinite fixpoint hierarchies.
F-limit points in dynamical systems defined on the interval
Given a free ultrafilter p on ℕ we say that x ∈ [0, 1] is the p-limit point of a sequence (x n)n∈ℕ ⊂ [0, 1] (in symbols, x = p -limn∈ℕ x n) if for every neighbourhood V of x, {n ∈ ℕ: x n ∈ V} ∈ p. For a function f: [0, 1] → [0, 1] the function f p: [0, 1] → [0, 1] is defined by f p(x) = p -limn∈ℕ f n(x) for each x ∈ [0, 1]. This map is rarely continuous. In this note we study properties which are equivalent to the continuity of f p. For a filter F we also define the ω F-limit set of f at x. We consider...
Flipping properties and huge cardinals
Flipping properties and supercompact cardinals
Folding theory applied to BL-algebras
The notion of n-fold grisly deductive systems is introduced. Some conditions for a deductive system to be an n-fold grisly deductive system are provided. Extension property for n-fold grisly deductive system is established.
Foldness of Commutative Ideals in BCK-algebras
This paper deals with some properties of n-fold commutative ideals and n-fold weak commutative ideals in BCK-algebras. Afterwards, we construct some algorithms for studying foldness theory of commutative ideals in BCK-algebras.
Fonctions Généralisées et Analyse Non Standard.