• Communications of the Korean Mathematical Society
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• v.15 no.3
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• pp.521-531
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• 2000

Graph C*-algebras C*(E) are the universal C*-algebras generated by partial isometries satisfying the Cuntz-Krieger relations determined by directed graphs E, and it is known that a simple graph C*-algebra is extremally rich in sense that it contains enough extreme consider a sufficient condition on a graph for which the associated graph algebra(possibly nonsimple) is extremally rich. We also present examples of nonextremally rich prime graph C*-algebras with finitely many ideals and with real rank zero.