Function sumo#probability_fn__probabilityfn (sumo#formula -> sumo#real_number)  one of the basic probability_relations, probability_fn is used to state the a priori probability of a state of affairs represented by the given formula
  type:  pm#unary_function_type  class of functions requiring a single argument; if R is functional, then if R(x -> y) and P(x -> z) then y=z
  type:  pm#total_valued_relation_type  when there exists an assignment for the last argument position of the relation given any assignment of values to every argument position except the last one; note that declaring a relation to be both a total_valued_relation and a single_valued_relation means that it is a total function
  type:  pm#asymmetric_relation_type  an antisymmetric and irreflexive relation
  type:  pm#probability_relation_type  the class of relations that permit assessment of the probability of an event or situation
  supertype:  pm#probability_relation__probabilityrelation (sumo#formula,?)
     supertype:  pm#relation_from_description (pm#description,*)
        supertype:  pm#relation_from_description_content/medium/container (pm#description_content/medium/container,*)
           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#asymmetric_relation (?,?)  this category only serves structuration purposes: it is instance of pm#asymmetric_relation_type which is not instance of pm#class_of_inheritable_relation_type
     supertype:  pm#irreflexive_relation__irreflexiverelation (?,?)  this category only serves structuration purposes: it is instance of pm#irreflexive_relation_type which is not instance of pm#class_of_inheritable_relation_type
        supertype:  pm#binary_relation_with_particular_mathematical_property (?,?)
           supertype:  pm#relation_with_particular_mathematical_property (*)
              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
                 >part of:  pm#relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type
     supertype:  pm#antisymmetric_relation__antisymmetricrelation (?,?)  this category only serves structuration purposes: it is instance of pm#antisymmetric_relation_type which is not instance of pm#class_of_inheritable_relation_type
        supertype:  pm#binary_relation_with_particular_mathematical_property (?,?)