  We give a short proof of almost sure invertibility of unsymmetric random
Kansa collocation matrices by a class of analytic RBF vanishing at infinity,
for the Poisson equation with Dirichlet boundary conditions. Such a class
includes popular Positive Definite instances such as Gaussians, Generalized
Inverse MultiQuadrics and Matern RBF. The proof works on general domains in any
dimension, with any distribution of boundary collocation points and any
continuous random distribution of internal collocation points.
