#regular_tetrahedron__regulartetrahedron  a tetrahedron with four equilateral triangular faces
  supertype:  regular_polyhedron__regularpolyhedron__regular_convex_solid__regular_convex_polyhedron__Platonic_body__Platonic_solid__ideal_solid__idealsolid  any one of five solids whose faces are congruent regular polygons and whose polyhedral angles are all congruent
     supertype:  polyhedron  a solid figure bounded by plane polygons or faces
        supertype:  solid.shape  a three-dimensional shape
           supertype:  shape__form  the spatial arrangement of something as distinct from its substance; "geometry is the mathematical science of shape"
              supertype:  space  point or extent in space
                 supertype:  spatial_object__spatialobject  object which as a direct spatial location, e.g., physical object, spatial region or shape
                    supertype:  object__entity_with_spatial_feature  spatial object (space, location or physical object) or description medium/container (e.g., string, language, image); in a 4D ontology, an object is something whose spatiotemporal extent is thought of as dividing into spatial parts roughly parallel to the time-axis
                       supertype:  entity  something that can be "involved" in a situation
                          supertype:  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:  physical__physical_thing  an entity that has a location in space-time; locations are themselves understood to have a location in space-time; click here for more details on the identical category sowa#physical_thing
                          supertype:  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:  partially_tangible__partiallytangible  A subcollection of cyc#SpatialThing-Localized and cyc#TemporalThing. Each instance of cyc#PartiallyTangible has a tangible (i.e. material) part and a temporal extent (i.e. it exists in time). It might or might not also have an intangible part. For example, a particular copy of a book is made of matter, has temporal extent, and also has an intangible part: the information content of the text markings on its pages.
                       supertype:  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:  individual__particular___supertype_of_1st_order_types  all individuals (for concepts or relations) are implicitely or explicitely instance of that type
                       supertype:  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

No statement uses or specializes regular_tetrahedron; click here to add one.