A. Karimi - Member of Faculty of Arak Azad University
P. Bayat - Member of Faculty of Tafresh Azad University

DAGs are the tools for presentation of parallel Algorithms. These get an algebraic Statement as an input and when the paths of arcs and modes flowed that works parallel, show output as a result. In this graph every mode and every arc shows data dependency. In fact DAGs are tools for the best approach of implementation of parallel operations. At the beginning of this graph, X, Y, parameters get and after processing and necessary calculations in output, We will have the statements that we wanted. In other hand there are different kind of symmetric and asymmetric in the nature, and symmetric events are suitable for our mind.

DAG, Symmetric, Algebra, Efficiency