There is a classical technique for determining the equilibrium probabi
lities of M/G/1 type Markov chains. After transforming the equilibrium
balance equations of the chain, one obtains an equivalent system of e
quations in analytic functions to be solved. This method requires find
ing all singularities of a given matrix function in the unit disk and
then using them to obtain a set of linear equations in the finite numb
er of unknown boundary probabilities. The remaining probabilities and
other measures of interest are then computed from the boundary probabi
lities. Under certain technical assumptions, the linear independence o
f the resulting equations is established by a direct argument involvin
g only elementary results from matrix theory and complex analysis. Sim
ple conditions for the ergodicity and nonergodicity of the chain are a
lso given.