Relation sumo#material__material_type_of (pm#substance_class,sumo#corpuscular_object)  all other mereological relations are defined in terms of this one; it means that the 2nd argument is structurally made up in part of the 1st argument; this relation encompasses the concepts of 'composed of', 'made of', and 'formed of'; for example, plastic is a material of my computer monitor; since part is a reflexive_relation, every object is a part of itself
  type:  pm#binary_predicate_type  the class of predicates relating two items - its valence is two
  supertype:  pm#relation_from_type (pm#type,*)  type of relations from a concept/relation type, i.e. in RDFS terminology, from a class or a property
     supertype:  pm#relation_from_collection (pm#collection,*)
        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 categorization
           >part of:  pm#relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type
        supertype:  pm#what_relation (*)
           supertype:  pm#wh-/how_relation (*)  this type permits to categorize relations according to the usual who/what/why/where/when/how questions ; this is a traditional but very subjective and ineffective way of categorizing relations 
              >part of:  pm#relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type