dually quasi-de morgan stone semi-heyting algebras ii. regularity

this paper is the second of a two part series. in this part, we prove, using the description of simples obtained in part i, that the variety $mathbf{rdqdstsh_1}$ of regular dually quasi-de morgan stone semi-heyting algebras of level 1 is the join of the variety generated by the twenty 3-element $mathbf{rdqdstsh_1}$-chains and the variety of dually quasi-de morgan boolean semi-heyting algebras--the latter is known to be generated by the expansions of the three 4-element boolean semi-heyting algebras. as consequences of our main theorem, we present (equational) axiomatizations for several subvarieties of $mathbf{rdqdstsh_1}$. the paper concludes with some open problems for further investigation.