#fatigue_crack__fatiguecrack  a crack in metal resulting from metal fatigue
  supertype:  #scissure__crack__cleft__crevice__fissure  a long narrow opening
     supertype:  #opening.space__gap  an open or empty space in or between things; "there was a small opening between the trees"; "the explosion made a gap in the wall"
        supertype:  #space.amorphous_shape  an empty area (usually bounded in some way between things); "the architect left space in front of the building"; "they stopped at an open space in the jungle"; "the space between his teeth"
           supertype:  #amorphous_shape__amorphousshape  an ill-defined or arbitrary shape
              supertype:  #shape__form  the spatial arrangement of something as distinct from its substance; "geometry is the mathematical science of shape"
                 supertype:  pm#space  point or extent in space
                    supertype:  pm#spatial_object__spatialobject  object which as a direct spatial location, e.g., physical object, spatial region or shape
                       supertype:  sumo#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:  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:  sumo#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:  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#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:  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

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