Relation pm#ternary_relation__ternaryrelation__ternary_only_relation (?,?,?)  relation with a fixed arity equal to 3; specialized by the SUMO ternary relations not categorized elsewhere
  exclusion:  pm#binary_relation  pm#quaternary_relation  pm#relation_with_variable_arity
  supertype:  pm#relation_with_particular_property  this rather fuzzy type permits to group categorization schemes less common than those covered by the previous sibling categories
  subtype:  pm#binary_function (?,? -> ?)  function that requires two arguments; currently not specialized by the  SUMO ternary relations since this seems useless (for now)
  subtype:  sumo#confers_norm__confersnorm (pm#thing,sumo#formula,sumo#objective_norm)  the 1st argument brings it about that the formula has the objective_norm
  subtype:  sumo#deprives_norm (pm#thing,sumo#formula,sumo#objective_norm)  the 1st argument brings it about that the formula does not have the objective_norm