process a process is a entity that unfolds in time, has temporal parts, and has objects that participate in the process. the process of diagnosing a problem condition, the process of walking down the street, the process of teaching a class is item in has item is a relation between an item and the collection in which it contained. role A role is a feature that describes a context-dependent behaviour. a teacher, a student, a catalyst, a substrate, a product, a patient is part of is part of is a transitive, reflexive and antisymmetric relation between a part and itself or a part and a whole. Simplified Upper Level Ontology SULO Michel Dumontier, Remzi Çelebi, Komal Gilani, Isabelle de Zegher, Katerina Serafimova, Catalina Martínez Costa and Stefan Schulz. SULO - a simplified upper-level ontology. Proceedings of the Joint Ontology Workshops (JOWO) - Episode XI: The Sicilian Summer under the Etna, co-located with the 15th International Conference on Formal Ontology in Information Systems (FOIS 2025), September 8-9, 2025, Catania, Italy 2024-11-11 2025-07-11 2026-04-12 Simplified Upper Level Ontology sulo The Simplified Upper Level Ontology (SULO) is ontology with a minimal set of classes and relations to guide the development of a personal health knowledge graph. 0.2.11 This work is partially supported by the AIDAVA project (GA 101057062), as part of the European Union's Horizon Europe research and innovation programme. active information object an information object is a feature that represents, is about, or encodes some information. time interval A time interval is a quantity for a continuous and bounded extent of time, characterized by a start time and an end time. feature A feature is any characteristic that stems from the intrisinc structure and/or context the capability to fly, a collection of cards, a measured height of 170cm. capability A capability is a feature that describes what an entity is able to do, under some set of circumstances. the capability to fly, the capabilty to reduce the activation energy of a chemical reaction, the capability to reason object An object is an entity that maintains its identity through time, and does not have processes as its parts. a heart, the function to pump blood, the role of a doctor has part has part is a transitive, reflexive and antisymmetric relation between a whole and itself or a whole and its part. at time existsAt a relation between any thing and the time in which it occurs at. is feature of is feature of is a relation between an internal, contextual, or externally attributed characteristic and some Thing. has item has item is a relation between a collection and an item contained therein. is in A binary relation where the object entity includes the subject entity within its spatial, temporal, structural, or conceptual extent. quality A quality is a feature that is intrinsically associated with its bearer (or its parts). the color of an apple, the smoothness of skin, the brightness of a star, the speed of an event has value has value is the (only) data type attribute to store the values of information objects. quantity A quantity is an information object that represents the magnitude (and unit) of an object or process. time time is a quantity pertaining to the duration of some interval of time or a particular instant of time (against some frame of reference). precedes A relation in which one process occurs prior to another process. is time of a relation between a time and an object that occurs within it. end time an end time is a time instant at the end of a process/time interval. is referred to in is referred to in is relation between an object that is the subject of an information object. collection A collection is an information object for which there may be zero or more items. a stamp collection, a murder of crows, the arm of a clinical trial has direct part has direct part is a non-transitive parthood relation that can be used to specify cardinality constraints between a whole and its parts. spatial object A spatial object is an object that occupies space a mountain, a planet, a photon, the lining of the stomach, the cavity of the stomach, the space between mars and earth is direct part of is direct part is a non-transitive parthood relation that can be used to specify cardinality constraints between a part and its whole. 0.0 is participant in is participant in is a relation to relate an object and the process in which it participates. is preceded by A relation in which one process occurs after to another process. has feature has feature is a relation between a thing and an internal, contextual, or externally attributed characteristic. refers to refers to is a binary relation between an information object and any other object that it mentions, describes, represents, encodes, or otherwise provides information about. has participant has participant is a relation that describes the participation of a (non-process) thing in a process. duration Duration is a temporal quantity that represents the extent or (non-negative) amount of time that elapses between two temporal points, typically the start and end of a time interval. unit a unit is a standardized quantity that is used as a reference for a particular quantity. time instant time instant is a quantity of time a particular moment in time. start time a start time is a time instant at the beginning of a process/time interval. contains A binary relation where the subject entity includes the object entity within its spatial, temporal, structural, or conceptual extent.