#A-horizon__A_horizon  the top layer of a soil profile; usually contains humus
  substance:  humus
  supertype:  soil_horizon  a layer in a soil profile
     supertype:  horizon  a specific layer or stratum of soil or subsoil in a vertical cross section of land
        supertype:  stratum  one of several parallel layers of material arranged one on top of another (such as a layer of tissue or cells in an organism)
           supertype:  layer  a relatively thin sheetlike expanse or region lying over or under another
              supertype:  region.location__part  the extended spatial location of something; "the farming regions of France"; "religions in all parts of the world"; "regions of outer space"
                 supertype:  location  a point or extent in space
                    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 A-horizon; click here to add one.