Abstract :
The Kronecker quiver K is considered, and the relations for the specialisation at q = 0 of the
generic composition algebra are given, as well as those for Reineke’s composition monoid. As a
corollary, it is deduced that the composition monoid is a proper factor of the specialisation of the
composition algebra. A normal form is also obtained for the varieties occurring in the composition
monoid in terms of Schur roots.
