stateswhat

Stateswhat is a theoretical modeling construct used in the study of stateful systems. It combines elements of finite-state representations with an explicit notion of the content carried by each state. The term stateswhat signals the idea that a state is not only a position in a machine but a snapshot of observable attributes that define the current situation.

A stateswhat model comprises a set of states S, a set of events or stimuli E, a transition relation T ⊆ S × E × S, and a labeling function L that maps each state to a set of predicates W describing its content. The contents may include modality, constraints, or environmental conditions, enabling richer specifications than conventional state machines. Transitions occur in response to events, optionally subject to preconditions on the state content, and produce a new content set via L for the target state.

In practice, the labeling L allows observers to query not only the active state but also its context, such as resource usage, time since last event, or user inputs. This makes stateswhat suitable for formal verification, runtime monitoring, and design of reactive systems where context matters for correctness or performance.

Examples frequently cited include simple control loops, human–in–the–loop systems, and IoT workflows, where the same active state can have different “what” content under varying conditions. Related concepts include labeled transition systems, statecharts, and temporal logic.

Open questions in the field concern expressive power, tractability of verification, and standardization of the labeling language.