The deep history of history states

The history state is likely one of the most magical and confusing parts of the statechart formalism, so we wanted to spend some time exploring the history of history state to help demystify it and figure out what its purpose it.

The first publicly known image of a history dates back to page 22 of Statecharts in the Making: A Personal Account. In this paper, David Harel reflects on his personal account of pioneering statecharts and we are lucky enough to see some of his earliest sketches of statecharts from around 1982.

The transitions leaving the history state that Harel erased reveals something fundamental about its nature.

But that doesn't mean that the transition is non-deterministic and breaks an important guarantee of statecharts.