The work realized by the authors of [4], [5] and [6] associates a non-negative matrix with positive integers entries to each dissection of a polygon. In the particular case of triangulations, these matrices called BCI-matrices here contain valuable information of their frieze patterns, a concept introduced by Coxeter and Conway. This paper is concerned with the algebraic manipulation and properties of these matrices which are derived from operations acting on dissections.

Keywords: BCL-matrices, non-negative matrix