11 Which team is winless?- Team 3 Graph Models: Precedence Graphs & Concurrent Processing Example 9: Computer programs can be executed more rapidly by executing certain statements concurrently. It is important to not attempt to execute a statement that requires results of statements that have not yet been executed. The dependence of statements on previous statements can be represented by a directed graph. Each statement is represented by a vertex and there is an edge from one vertex to a second vertex if the statement represented by the second vertex cannot be executed before the statement represented by the first vertex has been executed. Such a graph is called a precedence graph S: S: S3: S4 S5: S6: a == 0 b = 1 c= a +1 db + a e = d+1 e = c + d So Ss 14 SA S3 S1 What statements must be executed before statement S5 can be executed? S4, 5,51 7) Construct a precedence graph for the following program: S: x:= 0 S S: x:= x + 1 S3: y: = 2 S4: Z: = y S5: x:= x + 2 S6: y = x + z S7: Z: = 4 $30 S2 S