activityor

Activityor is a construct used in process modelling and workflow design to express a disjunctive choice between two or more activities within a control flow. It models situations where, upon reaching the construct, the system may proceed with one of several alternative actions.

Semantics and usage: In formal models, an activityor represents a disjunction over its operands: Execute A or B (and in some models, possibly both under inclusive semantics). The exact interpretation—whether the choice is exclusive or allows multiple concurrent outcomes—depends on the modeling framework and accompanying constraints. Activityor is commonly employed to represent nondeterministic decision points or conditional branching where multiple viable paths exist.

Notation and origin: Activityor is usually written as A or B or denoted with a logical OR symbol (A ∨ B). In domain-specific languages, it may appear as activityor(A, B) or as a labeled choice node within a workflow diagram. The term blends “activity” with the logical operator “or” and appears in discussions of action languages, workflow languages, and process algebras that support branching.

Applications: It appears across business process modeling, software workflow orchestration, robotics task planning, and game AI, where a system must select between alternative activities based on context, data availability, or timing.

Examples: In a customer onboarding flow, an activityor could represent choosing between “collect email” or “collect phone” depending on known contact preferences. In a robotic picking task, the system might select between “grasp” or “navigate around obstacle” based on sensor input.

Variants and related terms: Some formalisms distinguish inclusive versus exclusive semantics; an explicit exclusive form is sometimes referred to as activityxor. Documentation should specify the intended semantics for a given model.

See also: choice operator, nondeterministic choice, workflow, process modeling, planning.