Under the assumption that a residually finite-dimensional Hopf algebra H has an Artinian ring of fractions, it is proved flat module over any right coideal subalgebra satisfying polynomial identity and faithfully subalgebra. As consequence we find large class algebras which are all subalgebras subalgebras.

Not every quasihereditary algebra $(A,\Phi,\unlhd)$ has an exact Borel subalgebra. A theorem by Koenig, K\"ulshammer and Ovsienko asserts that there always exists a Morita equivalent to $A$ regular subalgebra, but characterisation of such representative is not directly obtainable from their work. This paper gives criterion decide whether contains subalgebra provides method compute all the repre...

With the aim of applying Dokdo structure to BE-algebra, notions (weak) BE-subalgebra and BE-filter are introduced, their properties investigated. The relationship between weak BE-subalgebra, is established. conditions under which can be BE-filter,and condition explored. Characterizations provided.

‎In this paper‎, ‎we investigate the invariant elements of the dual mod $p$ Steenrod subalgebra ${mathcal{A}_p}^*$ under the conjugation map $chi$ and give bounds on the dimensions of $(chi-1)({mathcal{A}_p}^*)_d$‎, ‎where $({mathcal{A}_p}^*)_d$ is the dimension of ${mathcal{A}_p}^*$ in degree $d$‎.