Thank you for the explanation. Time decomposition is a good point.
But What defines a computational graph(node, outgoing and incoming edge)? You provided two way to define a computational graph(with “procedural” and “object-oriented”).
And let’s take say we  have a leaf tensor T0 with initialized value, a math operation OP0 , a outgoing edge EG0 from T0 to OP0, a outgoing edge EG1 from OP0 to T1  and a outgoing edge EG2 from the output T1 to input T0( or directly from OP0 to T0).
Briefly,
T0 ====(EG0)=====> OP0 =====(EG1)====> T1
|<================<==(EG2)==============|
Will this graph I presented count as a valid and cyclic one?
Sorry for the bad “drawing” with these symbols.