Let 〈P,≤〉 be a partially ordered set. We define the poset Boolean algebra of P , and denote it by F (P ). The set of generators of F (P ) is {xp : p ∈ P}, and the set of relations is {xp ·xq = xp : p ≤ q}. We say that a Boolean algebra B is well-generated, if B has a sublattice G such that G generates B and 〈G,≤G〉 is well-founded. A wellgenerated algebra is superatomic. Theorem 1 Let 〈P,≤〉 be a...

The articles [6], [1], [4], [5], [2], and [3] provide the notation and terminology for this paper. Let O1 be an ordered affine space. Then Λ(O1) is an affine space. Let O1 be an ordered affine plane. Then Λ(O1) is an affine plane. We now state several propositions: (1) There exists a real linear space V and there exist vectors u, v of V such that for all real numbers a, b such that a · u + b · ...

in an earlier work we showed that for ordered fields f not isomorphic to the reals r, there are continuous 1-1 unctions on [0, 1]f which map some interior point to a boundary point of the image (and so are not open). here we show that over closed bounded intervals in the rationals q as well as in all non-archimedean ordered fields of countable cofinality, there are uniformly continuous 1-1 func...

let $s$ be an ordered semigroup. a fuzzy subset of $s$ is anarbitrary mapping   from $s$ into $[0,1]$, where $[0,1]$ is theusual interval of real numbers. in this paper,  the concept of fuzzygeneralized bi-ideals of an ordered semigroup $s$ is introduced.regular ordered semigroups are characterized by means of fuzzy leftideals, fuzzy right ideals and fuzzy (generalized) bi-ideals.finally, two m...

A relation ∼ describes how things are connected. That a thing a is related to a thing b can be represented by 1. An ordered pair (a, b). 2. An directed edge a• •b . 3. Or more commonly, simply using relational notation a ∼ b. A relation is 1. A set G of ordered pairs. 2. A directed graph G of nodes and edges. 3. A matrix of True and False values. Higher-dimensional relations among a, b, c or mo...

The statement "x>y" may be read "x dominates y." Transitivity is not assumed ; a transitive weakly ordered system is a partially ordered system. By a solution of a weakly ordered system is meant a set V of elements of D such that (a) XÇLV and y £ V implies x># for some yÇ~ V. The concept of solution was introduced in J. von Neumann and O. Morgenstern, Theory...

New high-pressure ordered-ilmenite and double-perovskite polymorphs of Mn 2 LiReO 6 are unprecedented A-site manganites with B/B? +/7+ oxidation states. They show cluster spin-cluster-glass behaviour giant coercivity without spin–orbit-coupling.

This lecture—based on the author's book, General Lattice Theory , Birkhäuser Verlag, 1978—briefly introduces the basic concepts of lattice theory, as needed for the lecture " Some combinatorial aspects of congruence lattice representations ". 1.1. Posets. A partially ordered set A; ≤≤ consists of a nonvoid set A and a binary relation ≤ on A such that the relation ≤ satisfies properties (P1)–(P3...

Let 5 be a commutative semigroup. For a, b £5, we say that a divides b (or b is a multiple of a), and write a\b, if either a = b or ax = b for some x£5. We say that a properly divides b if a\b and b does not divide a. We call 5 archimedean if for all a, b £5, a divides some power of b. It is known that every commutative semigroup is uniquely expressible as a semilattice of archimedean semigroup...