Look here for me using an independent attribute model with time as the important axis. The terminology is from here:

Jones, N. D., and Muchnick, S. Complexity of flow analysis, inductive assertion synthesis, and a language due to Dijkstra. In 21st Symposium on Foundations of Computer Science (1980), IEEE, pp. 185-190.

and is quite well known in the program analysis world, though less well known elsewhere.