In this paper, we prove that the algebra of an étale groupoid with totally disconnected unit space has a simple over field if and only is minimal effective function vanishes on every open subset null function. Previous work subject required to be also topologically principal in non-Hausdorff case, but do not. Furthermore, provide first examples not groupoids spaces. Our come from self-similar g...

Two families of q-Schur algebras associated to Hecke algebras of type D are introduced, and related to a family used by Geck, Gruber and Hiss [10], [11]. We prove that the algebras in one family, called the q-Schur algebras, are integrally free, stable under base change, and are standardly stratified if the base field has odd characteristic. In the so-called linear prime case of [10],[11], all ...

A piggyback duality and a translation process between this one and a Priestley duality for each subvariety of involutive Stone algebras and regular o-De Morgan algebras is presented. As a consequence we describe free algebras and the prime spectrum of each subvariety.

the notion of vague ideals in pseudo mv-algebras is introduced,and several properties are investigated. conditions for a vague set to be avague ideal are provided. conditions for a vague ideal to be implicative aregiven. characterizations of (implicative, prime) vague ideals are discussed.the smallest vague ideal containing a given vague set is established. primeand implicative extension proper...

Using a special set x−1F , we give an equivalent condition for a filter to be prime, and applying this result, we provide the prime filter theorem in lattice implication algebras. 2000 Mathematics Subject Classification. Primary 03G10, 06B10, 54E15.