sumo#constant_quantity  physical_quantity with a constant value, e.g., 3 meters and 5 hours; the magnitude (see magnitude_fn) of every constant_quantity is a real_number; constant_quantities are expressed with measure_fn, e.g., 3 meters can be expressed as (sumo#measure_fn 3 meter); they form a partial order with the less_than relation, since less_than is a relation_extended_to_quantities and less_than is defined over the real_numbers; the less_than relation is not a total order over the class constant_quantity since elements of some subclasses of constant_quantity (such as length quantities) are incomparable to elements of other subclasses of constant_quantity (such as mass quantities)
  closed_exclusion:  pm#function_quantity_type
  subtype:  sumo#time_measure
  supertype:  sumo#physical_quantity  a measure of some quantifiable aspect of the modeled world, such as 'the earth's diameter' (a constant length) and 'the stress in a loaded deformable solid' (a measure of stress, which is a function of three spatial coordinates); physical_quantities need not be material, e.g., amounts of money (in specified currencies) would be instances of sumo#physical_quantity
     supertype:  sumo#quantity  any specification of how many or how much of something there is
        supertype:  pm#attribute_or_quality_or_measure  e.g., mass, mass unit, 1 kg, frequency, [2-3] hz, color, blue, speed, 1 m/s
           supertype:  pm#non_spatial_object__nonspatialobject  abstraction or description content/medium/container (a description medium that has some spatial feature is both instance of sumo#object and pm#non_spatial_object
              supertype:  pm#entity  something that can be "involved" in a situation
                 supertype:  pm#thing__something___T__t___3D_or_4D_thing_or_anything_else  any category (type or individual) is instance of this type; any type is also a subtype of this type
              supertype:  cyc#intangible  The collection of things that are not physical -- are not made of, or encoded in, matter. Every cyc#Collection is a cyc#intangible (even if its instances are tangible), and so are some cyc#individuals.  Caution: do not confuse `tangibility' with `perceivability' -- humans can perceive light even though it's intangible--at least in a sense.
                 supertype:  cyc#partially_intangible__partiallyintangible  The collection of things that either are wholly intangible (see cyc#Intangible) or have at least one intangible (i.e. immaterial) part (see cyc#intangibleParts). This includes intangible individuals, such as instances of cyc#Number-General  or cyc#Agreement, as well as non-individuals (all of which are intangible), i.e. instances of cyc#SetOrCollection.  It also includes things that have both tangible and intangible components (see cyc#CompositeTangibleAndIntangibleObject),  such as a printed copy of a newspaper (as its information content is intangible) or a person (as her mental states are intangible).
                    supertype:  pm#thing__something___T__t___3D_or_4D_thing_or_anything_else  any category (type or individual) is instance of this type; any type is also a subtype of this type
           supertype:  pm#thing_that_can_be_seen_as_a_relation  usable as relation type
              supertype:  pm#thing_playing_some_role  category to classify things according to roles/viewpoints; classification under this category is application-dependant
                 supertype:  pm#thing__something___T__t___3D_or_4D_thing_or_anything_else  any category (type or individual) is instance of this type; any type is also a subtype of this type
           supertype:  pm#individual__particular___supertype_of_1st_order_types  all individuals (for concepts or relations) are implicitely or explicitely instance of that type
              supertype:  pm#thing__something___T__t___3D_or_4D_thing_or_anything_else  any category (type or individual) is instance of this type; any type is also a subtype of this type
        supertype:  sumo#abstract__entity_without_spatial_feature  e.g., knowledge, motivation, measure; properties or qualities as distinguished from any particular embodiment of the properties/qualities in a physical medium; instances of sumo#abstract can be said to exist in the same sense as mathematical objects such as sets and relations, but they cannot exist at a particular place or time without some physical encoding or embodiment
           supertype:  pm#non_spatial_object__nonspatialobject  abstraction or description content/medium/container (a description medium that has some spatial feature is both instance of sumo#object and pm#non_spatial_object

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