Document Type : Research Paper


Department of Mathematics, Faculty of Mathematics and Statistics, University of Birjand, Birjand, Iran.


In this paper, the special attention is given to the  product of two  modular operators, and when at least one of them is EP, some interesting results is made, so the equivalent conditions are presented  that imply  the product of operators is EP. Also, some conditions are provided, for which the reverse order law is hold. Furthermore, it is proved  that $P(RPQ)$ is idempotent, if $RPQ$ has closed range, for orthogonal projections $P,Q$ and $R$.


Main Subjects

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