Computational graph can represent expressions as graphs. For example,
a+b can be represented like the above figure. When we consider an expression with self-feedback, how can it be represented as a graph? For example,
dv(t)/dt=v(t)+i(t) can be solved as
v(t)=v(t-1)f(t)+i(t). It is possible to construct a graph with right-hand side. But, we also have to store the final result to a state variable
v. How to handle this issue?