well, it seems fork is some kind of builtin function that is intimately related to the bend construct: https://github.com/HigherOrderCO/bend/blob/main/FEATURES.

well, it seems fork is some kind of builtin function that is intimately related to the bend construct: https://github.com/HigherOrderCO/bend/blob/main/FEATURES.md#:~:text=%27fork%27%20calls%20the%20bend%20recursively%20with%20the%20provided%20values https://github.com/HigherOrderCO/bend/blob/main/FEATURES.md#.... so presumably the initial fork(0) state is implicitly produced by the bend