Consider, for example, the following code:The DFG allows the translation of a static control program into a single assignment program (see 3.1). In such a program there is no memory cell reuse. An important property of single assignment programs is that a reference to a memory cell can be replaced by its definition: this is the usual notion of forward substitution in systems of equations. Another method for computing informations equivalent to the DFG has been devised by Pugh and Wonnacott [18].Its Dataflow Graph is:DO i=1,n s(i)=a(i)*b(i) (v1) END DO s(0)=0 (v2) DO i=1,n s(i)=s(i-1)+s(i) (v3) END DOSource of s(i-1) in v3 ; * if [ i-2>=0 ] then (v3,i-1) * if [ i-1=0 ] then (v2) Source of s(i) in v3 ; * if [ true ] then (v1,i)