Abstract We introduce the notion of Raney morphism between MT-algebras and show that the resulting category is equivalent to the category of Raney extensions. This is done by generalizing the construction of the Funayama envelope of a frame. The resulting notion of the T₀ T 0 -hull of a Raney extension generalizes that of the TD T D -hull of a frame.
Bezhanishvili et al. (Wed,) studied this question.