A construction of dual box

Abstract

Let R be a quasi-hereditary algebra, F(∆) and F(∇) its categories of good and cogood modules correspondingly. In [6] these categories were characterized as the categories of representations of some boxes A = A∆ and A∇. These last are the box theory counterparts of Ringel duality ([8]). We present an implicit construction of the box B such that B − mo is equivalent to F(∇).