Geometrical Realisations of the Simple Permutoassociahedron by Minkowski sums

Abstract

This paper offers a geometrical realisation of simple permutoassociahedra, which has significant importance serving as a topological proof of Mac Lane's coherence. We introduce a family of $n$-polytopes, $PA_{n,c}$, obtained by Minkowski sums such that each summand yields to the appropriate facet of the resulting sum. Additionally, it leads to the correlation between Minkowski sums and truncations of permutohedron, which implicitly gives a general procedure for geometrical Minkowski-construction of any permutonestohedron.