sentence1: chen constructed irreducible representations of a leavitt path algebra l of a graph e using the sinks as well as infinite paths in e and showed that these representations are also induced by appropriate e-algebraic branching systems .
sentence2: expanding this , chen studied special types of irreducible representations of l k by using the sinks as well as the infinite paths which are not tail-equivalent in the graph e and he noted that these can also be considered as algebraic branching systems .