code: public boolean removeAllRelations(TemporalExtendedPropositionDefinition def) {
          for (Iterator<List<TemporalExtendedPropositionDefinition>> itr = this.defPairsMap.keySet().iterator(); itr.hasNext();) {
              List<TemporalExtendedPropositionDefinition> pair = itr.next();
              if (pair.get(0) == def || pair.get(1) == def) {
                  itr.remove();
              }
          }
          return true;
      }
docs: Removes all relations involving a temporal extended proposition
  definition.
  
  @param def
  a {@link TemporalExtendedPropositionDefinition}.
  @return <code>true</code> if all such relations were removed,
  <code>false</code> otherwise.