Relation pm#logical_relation__logicalrelation (description,description)
  supertype:  relation_from_description
  subtype:  and (description,description)
  subtype:  contextualizing_logical_relation__contextualizinglogicalrelation (description,description)
     subtype:  or (description,description)
     subtype:  xor__either (description,description)
     subtype:  implication__then___therefore__therefore (description,description)
        subtype:  equivalence__equivalentTo___iff__iff (description,description)
        subtype:  entails__entail (formula,formula)  the second argument is logically entailed from the first by means of the proof theory of SUO-KIF