FUNCTION: heralg[cartan_inverse] - the inverse of the Cartan matrix of a quiver algebra

CALLING SEQUENCE:
cartan_inverse(Q)

PARAMETERS:
Q - a quiver given by a quiverdata structure

SYNOPSIS:

• The function cartan_inverse(Q) computes the inverse of the Cartan matrix of the path algebra of the quiver Q. The columns of the Cartan matrix are the dimension vectors of the indecomposable projective modules.

• This function is part of the heralg package, and so can be used in the form cartan_inverse(..) only after performing the command with(heralg) or with(heralg, cartan_inverse). The function can always be accessed in the long form heralg[cartan_inverse](..).

EXAMPLES:

> with(heralg):

> cartan_inverse( [2,[[1,2,r]]] );

> Q := [ 3, [[1,2], [2,3,2]]];

> cartan_inverse(Q);