Functionsumo#where_fn__wherefn(sumo#physical,sumo#time_point -> sumo#region)maps an object and a time_point at which the object exists to the region where the object existed at that time_pointrelated_to: sumo#when_fn type: pm#binary_function_typeclass of functions requiring two argumentstype: pm#total_valued_relation_typewhen there exists an assignment for the last argument position of the relation given any assignment of values to every argument position except the last one; note that declaring a relation to be both a total_valued_relation and a single_valued_relation means that it is a total functiontype: pm#spatial_relation_typethe class of relations that are spatial in a wide sense, e.g., mereological relations and topological relationsupertype: pm#relation_to_spatial_object (*,pm#spatial_object)in WebKB, prefer using relations "from" a spatial objectsupertype: pm#spatial_relation_to_entity_with_spatial_feature (*,sumo#object) supertype: pm#relation_from/to_thing_of_common_kind (*)this type permits to categorize relations according to their signatures and hence offers (i) a concise way to set essential exclusion relations, and (ii) a systematic and easy-to-follow categorizationsupertype: pm#relation__related_thing__relatedthing___related_with (*)type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type