On HS=SH and Duality Theorems of Intuitionistic Descriptive Frames
Fan Yang

Abstract:
The variety of Heyting algebras has a nice property that
HS=SH. Heyting algebras are the algebraic dual of intuitionistic
descriptive frames. The goal of this paper is to define proper dual
notions so as to formulate this algebraic properties in the frame
language, and to give a frame-based proof of this property and some
other duality theorems.