Relation sumo#believes (cognitive_agent,formula)  the agent believes the proposition expressed by the formula
  type:  propositional_attitude_relation_type  the class of intentional_relations where the agent has awareness of a proposition
  supertype:  propositional_attitude_relation (cognitive_agent,formula)  intentional_relations where the agent has awareness of a proposition
     supertype:  intentional_relation__intentionalrelation (cognitive_agent,?)  relations between an agent and one or more entities, where the relation requires that the agent has awareness of the entity
        supertype:  relation_playing_a_special_role (*)  this type permits to categorize relations according to their roles ; this is a traditional but quite subjective way of categorizing relations
           >part of:  relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type