In this paper, we construct special radicals using class pairs of near-rings. We establish necessary conditions for a class pair to be a special radical class.
For ungraded quotients of an arbitrary Z-graded ring, we define the general PBW property, that covers the classical PBW property and the N-type PBW property stu
Let G be a universal triangle group, and H a subgroup of G such that the chamber system △H is a tight triangle geometryThen H, which is canonically isomorphic
Three different notions of geometric degeneration for finite dimensional alge-bras are compared.It is proved that for algebras A0 and A1 of same dimension,if A0
We study a free boundary problem of parabolic equations with a pos-itive parameter τ included in the coefficient of the derivative with respect to the timevari