Relation rst#contrast (pm#description_content/medium/container,pm#description_content/medium/container)  comparability and differences of two situations
  exclusion:  rst#circumstance  rst#solution  rst#elaboration  rst#cause  rst#effect  rst#definition  rst#comparison  rst#means  rst#condition  rst#otherwise  rst#interpretation  rst#restatement  rst#summary  rst#theme
  supertype:  rst#subject_matter_rhetorical_relation  rst#symmetric_rhetorical_relation
  subtype:  rst#antithesis (pm#description_content/medium/container,pm#description_content/medium/container)